You are probably familiar with the Exposing to the Right (ETTR) technique, where an image is intentionally captured as bright as possible in order to maximize the potential of a digital camera sensor. I recently came across some forum posts and articles on other resources that talk about Exposing to The Left (ETTL) and its benefits. In this article, I want to point out why ETTR is the only proper way to get good exposure from a digital camera and why terms like ETTL do not make any sense.
My purpose is not to create a provocative article, but rather to educate our readers on this important topic. Please keep in mind that this article is fairly technical and it is not for everyone.
Table of Contents
What is Proper Exposure?
A properly exposed digital image contains plenty of information to be able to recover both highlight and shadow detail. This means that the image should be neither grossly overexposed to the point of losing highlight detail, nor underexposed to the point of losing shadow detail. The “feel and look” of an image in terms of its brightness is a whole different matter – a properly exposed image can be developed to intentionally look brighter or darker, depending on what the photographer is trying to achieve.
Ideally, an image should have the least amount of noise in both highlights and shadows once post-processed, with enough dynamic range to cover the whole range of darks and whites.
In order to maximize signal-to-noise ratio and get the least amount of noise in images, you should overexpose your image as much as possible, without blowing out any highlights. Simply put, the more of the image is distributed to the right of the histogram, the better. This is especially important for the shadows, because that’s where you are likely to see the most amount of noise in your images when you recover them through post-processing software.
All this means that on a modern digital camera sensor, the ideal exposure should be shot at the base ISO of the camera, and the scene should be exposed as brightly as possible, which is what the ETTR technique is all about.
However, some scenes, particularly high contrast ones, might have such a wide range of highlights and shadows, that they might not fit the dynamic range capabilities of an image sensor. In such cases, as we will see below, there is simply no such thing as “proper exposure” using a single image. The only proper way to correctly capture both highlights and shadows, will be to split it into two or more images.
Fuji GFX 50S + GF 110mm f/2 R LM WR @ 110mm, ISO 100, 1/450, f/2.5
There are also cases where “proper exposure” is all about capturing the details of a particular subject, while ignoring the rest of the scene (as is often the case with portraiture).
ETTR Histogram Examples
Unfortunately, ETTR is misunderstood by many photographers, because they think that ETTR images always show a curve to the right of the histogram. That’s certainly not the case! ETTR is all about getting proper exposure for a digital sensor, which means retaining data, not losing any of it. Hence, if most of the image is to the right of the histogram, but some parts of the image are getting blown out, that’s not ETTR – that’s overexposure.
Let’s take a look at a few images and their corresponding histograms to understand how wide the range of ETTR histograms can be:
Those who do not understand how ETTR works would only qualify the rightmost image to be ETTR, purely because of the way the histogram appears. However, both left and middle images are also shot using the ETTR technique.
Although the leftmost image appears very dark in the shadows and there seems to be some clipping of the darks, it was exposed to be as bright as possible while keeping highlights from blowing out. The middle image contains a range of tones, and although it shows a pretty big spread in the middle of the histogram, the rightmost side of it shows that the highlights were fully preserved.
All three images have something in common – they are exposed to take advantage of a modern digital sensor. However, there is certainly a problem with the left image – its darks are very underexposed and there might be some clipping taking place there, which is not ideal. In such cases, the dynamic range is too wide for the camera to be able to effectively capture both sides of the histogram. The solution is to capture multiple images and blend them together via HDR / Exposure Blending techniques, which I will discuss below.
Exposing to the Left: Film vs Digital
Film photographers sometimes “Expose to The Left”, because there is more leverage in the highlights than in the shadows when using negative film (such as silver-based black-and-white). With such film, you can recover a few stops in the shadows, but the real recovery potential is in the highlights, where even 8+ stops of overexposure is workable. Because of this, it makes sense to ensure that shadows are not very underexposed, since that’s one area that is tough to pull during development.
Digital, on the other hand, has great tolerance to underexposure, with its ability to recover 6+ stops in the shadows, while the highlights are typically clipped at just a couple of stops of overexposure.
To summarize, with film, you expose for the shadows and develop for the highlights. Whereas with digital, you expose for the highlights and recover the shadows.
The above chart is a very rough approximation of film vs digital response to under- and over-exposure. As you can see, film has more legroom in the highlights, while digital has more legroom in the shadows.
Let’s take a look at a couple of images below:
The “before” image above was the result of intentional underexposure to show off the dynamic range capabilities of a digital camera. The “after” image is what it looked like after 5+ stops of exposure recovery. The histogram, at the time of capture, looked very far to the left, appearing quite clipped, and yet it retained so much information.
All this essentially means that we should be worrying more about the highlights vs the shadows when shooting with digital cameras. By pushing our exposure as much to the right of the histogram as possible without blowing anything out (ETTR), we make sure that maximum information is retained at each pixel. This might result in a histogram that appears quite left-heavy, but that’s OK, because we have plenty of leverage in the shadows.
Speaking of which, the histogram is not particularly useful for assessing the recovery potential of the shadows in digital cameras. Even though the histogram for the “before” image above appears completely to the left, indicating severe underexposure, there is quite a bit of data residing in those shadows, as evidenced from the “after” image and its histogram:
Very little data is actually clipped here, which is remarkable. The good news is, most modern digital sensors have superb dynamic range and are capable of such recovery.
The Problem with “ETTL”
So where does this leave Exposing to the Left? Not in a good place for sure! Trying to expose for the shadows has no benefits on digital camera sensors. By pushing the histogram to the left, you are simply underexposing the image, which is going to end up hurting the overall image quality of the photograph once it is post-processed.
Take a look at the below images:
Here, the “before” image was captured with the ETTL technique, which was roughly two stops underexposed compared to ETTR. Once both images were post-processed and matched in brightness, it is clear that the “before” image contains a lot more noise compared to the properly exposed “after” image.
This proves that underexposing images is not a good idea in digital cameras. In almost every case, your goal should be to make the image as bright as possible, not the other way around!
The interesting thing is that many photographers are so confused about ETTL, that they often refer to ETTR as ETTL, just because of what they see in their histograms.
There is No Such Thing as “ETTL”
Some photographers argue that ETTL can be useful for portraiture, because ETTR often results in subject underexposure, which leads to too much noise on the subject’s face after the shadows are recovered.
Photographing people is obviously different from photographing landscapes. While landscape photographers do their best to make sure that all highlight and shadow details are preserved, that’s not a typical priority for portrait photographers. When doing portraiture, photographers focus on the subjects, making sure that they are properly exposed, as they are the “highlight” of the photograph. As a result, these photographers are probably going to expose for the subject and ignore potential overexposure issues, which could be seen in the foreground or the background, or both.
So, would such cases be referred to as “Exposing to The Left”? After-all, the shadows are much brighter and the histogram appears heavy to the left? No, this is still ETTR!
If you are purposefully making your image brighter to expose for what’s important (your subject), while completely ignoring some parts of the image that might be blowing out, you are still using the ETTR technique. Because your end goal is to reduce image noise, which is the essence of ETTR.
Fuji GFX 100 + GF 110mm f/2 R LM WR @ 110mm, ISO 1000, 1/500, f/2.8
For the above headshot, I exposed for the subject. If my goal was to preserve all the highlights in that small part of the sky on the top of the image, my subject would have turned out very dark and I would have ended up with an unnecessary amount of noise in the shadows. This would have been especially bad at ISO 1000, which is noisy “as-is”.
By letting the small part of the sky blow out (which is out of focus anyway), I might not be following ETTR strictly, but that’s because I made that choice. Losing a little bit of highlight detail is not a problem, since it does not change the essence of my photograph and that part of the sky is not particularly distracting to me. What’s important, is that I am making my subject look their best with the help of ETTR.
So, for those photographers who intentionally overexpose their images to get better shadow detail – you are using ETTR, not ETTL.
In fact, I would argue that there is no such thing as “ETTL”. ETTR is a technique to get the best out of your image sensor. ETTL is simply “underexposure”, with zero benefits. That’s all there is to it. And no, there is no such thing as ETTM (Exposing to the Middle) either. Stop looking at the histogram and making up terms please :)
High Dynamic Range Scenes
If the dynamic range of the scene is so wide that ETTR results in a severely dark image, some of the shadow detail might be getting lost / clipped. In other cases, recovering that shadow detail is going to add too much noise to the image. In such circumstances, a single ETTR exposure is simply insufficient and two or more exposures must be taken in order to recover shadow detail. That’s what specific camera and post-processing techniques are for.
Landscape and architecture photographers will often bracket their cameras in order to get three or more images that cover both highlight and shadow areas of the scene. These images are then brought into post-processing software in order to be merged together into a single HDR image. Other times, two or more images can be blended together using Luminosity Masks. In cases of extreme exposure recovery, or when high ISO is used (with noise and other artifacts showing up in the shadows), other techniques such as “image averaging” can be used to reduce noise and improve the overall quality of the image.
Fuji GFX 100 + GF 23mm f/4 R LM WR @ 23mm, ISO 200, 1/10, f/8.0
In short, not everything can be captured via a single shot ETTR technique, which is something you always have to keep in mind.
Hope you found this article useful. If you have any questions or concerns, please let me know in the comments section below!
Thank you for this well written explanation. While I am familiar with this topic, comfortable with and fully understand the logic and technical info behind it, this is the clearest and most concise explanation I have read. It is thorough, easy to read and easy to understand. I can readily refer others to this article if they want to better understand ETTR.
Thank you for another useful post!
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Thank you for this helpful article. I am shooting my d810 in highlight weighted metering mode. I aim for base iso in my shots and find that although exposures look a little dark compared with other modes i can get great results by brightening the shadows with the lightroom slider.
I am so happy with the results that this is my default way of working. I shoot mainly landscapes.
I was wondering where the highlight weighted mode fitted in on the eetl eetr spectrum!
Ken. I do the same thing now. Camera sits in highlight mode and I will usually bracket 2 or 3 shots to be safe. But using this method I can spend more time running around trying different angles rather then tweaking settings! I also find if I set my bias up +.3 or +.7 that the highlights can still be fully recovered on my D850 allowing for a near perfect exposure in one shot.
Ken. I do the same thing now. Camera sits in highlight mode and I will usually bracket 2 or 3 shots to be safe. By using this method I can spend more time running around trying different angles rather then tweaking settings! I also find if I set my bias up +.3 or +.7 that the highlights can still be fully recovered on my D850 allowing for a near perfect exposure in one shot.
Thanks for this Jeff
Having read these fascinating comments i now feel a lot better informed!
I have just reviewed around 400 shots on my d810, taken in a variety of light and dark situations using the highlight blinkies view. (I was unaware of this feature before reading this article!)
In almost all situations there are a tiny amount of blinkies (less than 1%) eg the edges of leaves in the sunlight etc. But in the final image after post processing I get a completely satisfactory image.
So I am beginning to think that the nikon highlight weighted metering mode is doing a good job of capturing as much data on the sensor as possible. A very useful feature!
The recent colour noise reduction article by Spencer has also been a revelation and I have set the default to zero as a result.
Highlight metering is meant to properly expose the highlights such as when your subject is lighted by a spotlight. For ETTR you would need to add some exposure as you did.
Highlight weighted metering is a great feature but can lead to underexposure if there is an unwanted bright spot in the frame which will lower the exposure possibly at the expense of optimally exposing the main subject. As ever, the human brain needs to direct the dumb meter to do the right thing!
With the Z6 I’m using highlight-weighted matrix mode with +1EV as a default for outside shooting. I’m tweaking a tone curve to go with it to lift the shadows. So far, works really well…
Nice article on ETTR. I think it’s one of the hardest things for a new photographer to understand. There is no perfect histogram, every photograph is different. ETTR is dependant on what in each photograph to expose correctly. You gave a nice example of using portrait photography. Finally, sometimes the conditions dictate that the only way to capture the scene is to bracket. I will say that the newer sensors really allow users more flexibility. It’s hard to believe the dynamic range of today’s technology.
Thank you for this article – it has come just at the right time for me as I was experiencing exactly what you were describing. Now, with this information, I hope to start improving how I expose my images.
Great article Nasim,
Maybe the today non-sense ETTL has also an historical reason. The first digital CMOS sensors had pattern noise in the highlights, this came from a variation of gain from pixel-to-pixel, the variation being more pronounced in the highlights (because of the multiplicative factor).
This kind of noise is now almost gone (and was possible to calibrate before anyway).
Good article, I greatly enjoy articles that teach better photography technique.
ETTR makes perfect sense, a photographer should want to fill up the photosite well with as many photons as possible, to give maximum information, without overflowing, which essentially has no information.
On my Nikon D850 I’m typically exposing just to the point where I don’t have the “blinkies,” but I will allow some blinkies if they are not distracting, smallish, and are not important to the image.
Obviously our camera histograms are JPEG, do you have any tips on using the JPEG histogram to properly expose a raw image?
Mark, keep in mind that the blinkies are based on the JPEG image and there is always some leverage there. Personally, I push my image to be as bright as possible, then introduce some blinkies intentionally (at 1/3 or 2/3 of a stop), because I know I have more leverage to recover those details in RAW. There are many ways to get JPEG histograms / blinkies to look more accurate by utilizing “flat” picture profile, etc, but I don’t like them, because they give me an unrealistic and very flat look on the back of the camera.
I think with every camera one can learn to push its boundaries. That’s the ideal way to get the best possible exposure :)
Hi again Nasim,
Thinking a bit more about it there is a room for ETTL, sometime I am doing it, in such conditions:
– raw
– aperture set for d.o.f. and/or maximum light gathered
– shutter speed to its minimum for max light and *no* blur movements
– rush capture
Aperture and shutter-speed basically set up the picture SNR.
ISO 800 (brightness in post) or 3200, for instance, will not change the SNR (ISO invariant).
In such condition, I prefer to ETTL with ISO, because it will not change SNR and it allows me to conserve a higher DR and not to blow highlight I would not have time to adjust.
Often I do it with manual setting + auto ISO + exposure compensation to -1 or -2 to give me more DR.
(by the way doing that is exactly like shooting at DR200 or DR400 on the Fuji)
Sly, I think there are exceptions to all situations. In the case of ETTR, it leads to proper exposure, but if it reduces shutter speed to the point of making the image unusable, then ETTR is not the answer. In such cases, shooting an underexposed image that will likely be noisy (but better than with motion blur) or shooting multiple images and combining them together is going to yield better results. Please see my responses below for more detail.
“, I think there are exceptions to all situations.”
Yes, so it makes the ETTL not a “Myth” but an exception.
You missed understand me I think. When setting aperture and shutter speed to its nominal values (d.o.f and no-motion blur) you can move to the left the histogram by lowering iso intentionaly because it has (almost) no impact on the final noise and gives more room for dynamics: eventual highlights coming into the frame. It is just free to do so (if you shoot raw of course) and is an ETTL as the histogram depend on amplification (iso).
“combining images” is the same thing than a slower shutter speed, for moving subject it leads to motion blur.
Thank you for this well written article and your knowledge sharing Nasim. I think I saw the ETTL post, or one of them, recently, on another site. It was very misleading. I hope more people read this post and ‘get’ the way a modern imaging sensor works. I always try to get as much light into the sensor as possible without clipping, unless, as you make a point of, the subject is the focal point and careful exposure of that person or object is what matters most, in which case, clipping of highlights and muddy shadows do not matter. Of course, rules were made to be broken as long as you know you are doing so :)
Brandon, thank you for your feedback! ETTR is really great once one understands its benefits, and it is really easy to implement on any camera.
Nasim
Good article. I am new to DSRL camera and been ETTL and I need to try ETTR. What you stated makes sense. I am going to assume the same is true for mirrorless camera.
Zigman, yes, it works for all digital cameras.
Nice try Nasim. Unfortunately, the arguments can be 100% reversed to claim that all pictures should all be ETTL if you assume that your subject requires you to always meter on the shadow areas and your picture has large DR. You could just as equally claim ETTR doesn’t exist unless you are able to use highlight metering and point your sensor at the highlight area only, since all meters are oversensitive to highlights. Unless you discuss every single type of scene, lighting condition and metering used beforehand, any exposure recommendation is meaningless. For example, are you saying a sports photographer should never use ETTL to protect shutter speed? How about a portrait photographer in a studio going for the Film Noir look? It would be far better to say something like ‘If your camera allows highlight metering, or you have a very flat scene, ETTR can help protect shadow detail. However, if your camera doesn’t have highlight metering, and the scene has high DR, then it is most important to select the appropriate metering method to protect both shadow and highlight detail.’ Blown-out highlights remain the most difficult to recover.
Burghclerebilly,
“Unfortunately, the arguments can be 100% reversed to claim that all pictures should all be ETTL if you assume that your subject requires you to always meter on the shadow areas and your picture has large DR.” I don’t think so :) If you end up metering on the shadow areas, you are simply going to blow out the highlights in those scenes with large DR. The proper way for a single exposure is ETTR, since you know you have very little legroom in the highlights and a lot more in the shadows. If the idea is to preserve the shadows without much noise, then the correct exposure would be spread across two or more bracketed images…
As for highlight metering, you don’t really need it to ETTR. Every modern camera comes with a histogram and blinkies to roughly judge the camera-created JPEG. Pushing the image as bright as possible while knowing what to let blow out (recoverable data in RAW) is enough to get the optimal exposure.
I do, however, agree with your statement about “exposure recommendation” for different types of scenes and lighting conditions. That’s why if you re-read the “proper exposure” section of this article, I use such words as “ideally”, because I am making a general statement, which does not include all scenes and shooting scenarios. I provided a section on portrait photography for this very reason, because in some scenes it is OK to blow out the highlights and push exposure even further to the right.
“For example, are you saying a sports photographer should never use ETTL to protect shutter speed”. Just like I provided an example where a portrait photographer intentionally chooses to overexpose the highlights, other types of photography can choose to go the other way around to increase their shutter speed, while counting on the capabilities of their camera to recover the shadows. In this particular case, it is not about getting the “optimal exposure” (which is what this article is about), but rather saving the shot by increasing the shutter speed.
Your last sentence says it all :)
Dear Nasim,
thank you for that article. I agree with your ETTR statement and try to do it the same way. One thing I have experienced and try to consider is wether the sensor of the used camera is iso-invariant or not. If it is not, like on the Leica Q, you might want to expose to the left side in low light. Otherwise you get a lot of noise and banding which is not recoverable. Of course you will then have to pray for the right side.
Greets Dirk
Dirk, I know the discussion of ISO invariance would come up and here is my argument to support the article – it does not matter! Whether your camera is ISO invariant or not, you are still going to push your base (reference) exposure as far to the right as possible before you decide to reduce ISO.
Now if your camera is not particularly great at recovering shadows due to limited dynamic range, then the only proper way to capture the image is to spread the dynamic range over 2 or more images. Otherwise, you will either end up sacrificing the highlights, or the shadows.
This was interesting. I also hate camera noise and feel that if I need to jack up the ISO over 400 that scene is not worth pointing my camera at it, since it would not be a usable image, and wasting the potential of my camera. I shoot at the base 64 ISO at least 90% of the time for better color saturation as well, but also push for a medium to high aperture unless my subject is over 100 feet away. I have never paid attention to the histogram. I know if I overexpose a subject it is often not something I can recover in post. I encourage others to practice shooting in full manual at the lowest possible ISO to help train their eye to be a good light meter, and develop an understanding of their controls to know what they can afford to sacrifice in low light.
Although, I find that most people have no idea how to do any post processing work to an image, or just not willing to put in the time it takes, and rarely willing to learn what the controls mean. Just shutter speed is daunting to most, so we now live in the age of smart-phone pics, and they can think they are a serious photographer.
David, thank you for sharing. Shooting at base ISO is the best you can do, but don’t let higher ISO be a show stopper for you. Over the years, I captured many amazing images that were shot at higher ISOs. Just a few years back, we didn’t have ISO 64 and the base ISO of a number of cameras was 200 :) Things have changed a lot since then and we are dealing with truly ground-breaking cameras with unbelievable dynamic range.
With ETTR, you don’t have to look at the histogram. I personally rarely ever do. I turn on my exposure warning / blinkies and push my exposure as bright as possible until something starts to blink. At that point, I know that I still have a potential leverage of a stop or more in post.
Nasim, I think you confused yourself here, referring to ETTL: “By pushing the histogram to the left, you are simply underexposing the image.” In fact, in ETTL, you are “dragging the histogram to the right, so that it is not clipped on the left.” This leads to overexposure of the image.
Pete, I don’t think I did :) What does the histogram of an underexposed image look like? If you are dragging the histogram to the right, so that it is not clipped on the left, you are doing ETTR (hence the name). But you are right as well – in high contrast situations, ETTL often leads to overexposure.
In the old (dark?) days I exposed Tri-X at ISO 200 and developed for a flat neg (Rodinal 1:50, 6 min, agitate 5 sec per 30). Printing on a high-contrast #4 paper meant less noise than if I had developed for a higher-contrast negative. It’s kind of what I aim for with digital – a nice flat RAW image that minimizes shadow grain without blowing the highlights. And, well, gee, isn’t that what Ansel Adams did? But I remind myself, “Let’s be real.” With digital it’s so easy to twirl the exposure compensation settings. If the highlights are more important than the shadows, hubba-hubba, I’m all over that by underexposing, and vice versa. No hard-and-fast rule, just dance all over the camera settings. Cheers, Nasim.
It was due to an earlier ETTR explainer in Photography Life by Spencer Cox and a really great video on ETTR by Nigel Danson that for me, a beginner photographer, the penny finally dropped – a RAW file is not a photograph and ETTR is the best approach for collecting the optimum data set of light from the scene in front of your camera, so you can then have a better chance of turning the RAW file into a half way decent photograph (assuming subject, composition, focussing etc are OK). So Nasim – thank you for a great reminder/reinforcement of the benefits of ETTR. And also thank you for the explanation in this context of the difference between film and digital – fascinating!
Glad you found the article useful Tony, thank you for dropping by and leaving your feedback, we really appreciate it!
Great and very useful article, as usual. There is always something new to learn on this site. After shooting for some three months with my Z6, I find it now much easier to deal with the exposure through the great EVF compared to DSLR. Shooting the moon, for example, is much easier as well as all sorts of HDR scenery. We are really spoiled with digital compared to the film times.
Nasim, although I am not a young guy and have done a lot of (amateur) film shooting in the old days, I never managed to get a proper shot of the moon on film. How was it done in the old days?
Niko, glad you’ve enjoyed the article. In regards to shooting the moon, I think the Looney 11 rule has been working great for moon photography for both film and digital. The biggest issue is focusing and making sure that the moon looks very sharp…
Thank you for this perfect and professional explanation.
The best one I ever read for this exposure techniques.
No, you are in both the article and the response misrepresenting what ETTL is. Or you are claiming you have invented ETTL.
ETTL is finding the ideal exposure then increasing it (if possible) to the point where the highlights aren’t clipped in order to maximise digital information. It is not finding the correct exposure and adjusting it either way to ensure highlights aren’t clipped. That would be classed as careful metering. Your tital misrepresents ETTL and ETTR.
Billy, I really think you got the two flipped in your mind. ETTR is pushing the exposure to the right without blowing out the highlights:
photographylife.com/expos…-explained
luminous-landscape.com/expose-right/
Quoting the great Michael Reichmann (RIP): “The simple lesson to be learned from this is to bias your exposures so that the histogram is snugged up to the right, but not to the point that the highlights are blown”. So if you have a scene with a wide dynamic range where the highlights are already very bright, an image that is spread towards the left of the histogram or its middle, while the highlights are barely touching the right, is still an ETTR image. It is not ETTL, just because a lot of the data is pushed against the right. The whole point is to make the image as bright as possible without sacrificing data. That’s our definition of ETTR here at PL and that’s what we teach to our readers.
Now quoting your own words back to you: “ETTL is finding the ideal exposure then increasing it (if possible) to the point where the highlights aren’t clipped in order to maximise digital information”. If we go by your definition, this would result in data being pushed as far to the right as possible in the histogram, which is the very definition of ETTR.
Forgot to add one more thing – the term “Exposing to the Left” is relatively new and it came out way after ETTR was defined. There is not a single authoritative source that speaks about ETTL, and for a good reason – it simply doesn’t exist and it is a new invention :)
Nasim,
You have my humblest apologies! I don’t usually get my L and R confused, must have been a long day at the office! If you re-read my synopsis you will see it made sense:
ETTR is finding the ideal exposure then increasing it (if possible) to the point where the highlights aren’t clipped in order to maximise digital information. It is not finding the correct exposure and adjusting it either way to ensure highlights aren’t clipped. That would be classed as careful metering.
The point remains true for both ETTL and ETTR. Neither should be used as general exposure recommendations without prior consideration of the genre of photography, the lighting conditions and the metering being used. It would be like saying ‘Vivid is always a better JPEG colour profile than Standard’ or ‘Cloudy is always a better white balance than Sunny’. ETTL and ETTR are exposure modification options, just like high or low contrast is, or using a graduated filter. They might be appropriate to use 5% or less of the time, but not generally.
On the other hand, adjusting exposure to avoid clipping highlights, or losing shadow detail are neither ETTL or ETTR, they are simply good ‘normal’ exposure techniques, indeed similar to simply the dilligent choice of metering mode. Take a look through the excellent Michael Freeman’s Guide to Perfect Exposure, and you will see scores of techniques to use in diffeerent situations (not to mention thousands of great shots), which involve moving the histogram one way or the other, but there is no mention of ETTL or ETTR being an overriding superior technique.
Your final comment really shows where the confusion comes from:
‘Forgot to add one more thing – the term “Exposing to the Left” is relatively new and it came out way after ETTR was defined. There is not a single authoritative source that speaks about ETTL, and for a good reason – it simply doesn’t exist and it is a new invention :)’
No, ETTL has been around just as long as ETTR, which is at least 60-years from a documentary perspective and probably over a 100-years in use. Similar to the current digital technique of managing noise in a shot, pushing or pulling exposure could be done at at least four stages in film photography, to manage the technical issues of development and/or achieve a wanted style. But no one ever applied ETTL or ETTR as a general exposure technique. Just because you haven’t found something on the internet, it doesn’t mean it doesn’t exist! ;->
Hahaha, you guys confused me quite a bit. It is all in the mathematics of the analogue to digital conversion process. Please have a loot at page 4 of this PDF: gui2-for-exiftool.weebly.com/uploa…_rev_d.pdf It is graphically explained and very easy to understand this way. I searched quite a while for some good explanation.
Nasim, thanks for your article and Burghclerebilly for your contribution. Never mind the mix of left and right.
Let us all shout out loud: WE WANT RAW RGB-HISTOGRAMS!
Cheers! -jan
Burghclerebilly, we are just going to have to agree to disagree, as I don’t have the time to go back and forth about this :)
Now that you have properly defined ETTR, please re-read the article, as that’s exactly what I point out in the article: “All this means that on a modern digital camera sensor, the ideal exposure should be shot at the base ISO of the camera, and the scene should be exposed as brightly as possible, which is what the ETTR technique is all about”. I make several references to such statements in the article. Spencer’s article on ETTR also spells this out in the exact way.
ETTR is the only proper way to expose images on a digital sensor. That’s how you saturate the sensor pixels with more data and end up with a better image, each and every time. Are there exceptions to this? Of course, just like with any general “rule”. The need for faster shutter speed, the total disregard to some parts of the image (as presented in the article), as well as some other situations call for occasional disregard for recommended exposure. That’s why there is a whole section devoted to this in the article, as I wanted to make sure to point out about such situations.
“No, ETTL has been around just as long as ETTR, which is at least 60-years from a documentary perspective and probably over a 100-years in use”. Sorry, but the ability to see the histogram after capture and modifying the exposure only came with digital. It did not exist with film – you only had a light meter to judge exposure. Could a film photographer use the light meter to adjust exposure and make sure that shadows are not severely underexposed? Of course, but it was not called ETTL! I think this is the source of confusion – you are referring to the technique of underexposing / overexposing whole or parts of the image, and I am talking about the terminology used to saturate a digital sensor. The two are not the same, as the latter is only valid for a digital camera. Again, please re-read the whole article, specifically the section about film vs digital and how the two differ in their exposure latitudes.
Underexposure makes sense, ETTL doesn’t…
Just wanted to point out after reading the first sentence, I hope it didn’t come out arrogant – I wasn’t trying to say that I don’t have time for you. Hope my comment didn’t offend you, and if it did, I apologize!
No worries Nasim, I know where you are coming from.
There is potential for confusion about the history and current status. Just because the expression Expose to the Left has been more often abbreviated in recent years to ETTL, it doesn’t mean the concept has suddently changed to be only about optimising digital sensor performance. It is still just one possible exposure technique among dozens aimed at creating the best exposure in the specific lighting conditions you are faced with and metering methods available. As I explained, monitoring your shadows and highlights and over or under-exposing for clipping is just good exposure practice. But ETTL is also a valid and historic exposure option when you need to preserve high shutter speeds, you’re shooting a low-light style scene, you want to maintain low ISO characteristics (not every photograph needs to have a centred histogram), or you have rapidly changing light and you don’t want to lose highlights. Similarly, ETTR can equally be useful in various situations, especially if you can meter for highlights, but it is not a panacea either. The following two articles discuss both ETTR and ETTL and come to the same conclusion – it depends on the facts and circumstances.
prolost.com/blog/…right.html
improvephotography.com/47886…t-for-you/
Stating that ETTL is ‘wrong’ is a meaningless statement without describing the facts and circumstances of the image, and claiming it is a ‘recent invention’ is simply not true. It reminds me of the ‘discussion’ around whether ISO should be part of the exposure triangle a few years ago. Some modern theorists got excited when they learned that ISO was just electgronic gain so in their view was not relevant to optical light gathering (exposure). Meanwhile people who actually take pictures still consider ISO as part of the exposure triangle. It would be better to take discussions about purely optimising sensor performance away from terminology routed in optimising photographic exposure.
Burghclerebilly, ETTR is a technique to get the most out of a digital sensor. ETTL is underexposure. There is no other way to put it, because every ETTL example I have seen looks like the one provided on the second link – a clearly underexposed image.
There is nothing wrong with underexposing an image in such situations as described earlier, such as when maintaining of fast shutter speed is required. However, even in such situations, it is done as a compromise – if a photographer needs to keep the shutter speed at a particular speed and CAN keep the exposure bright enough to have better post-processing options, he would.
I read both of the links you provided. On the first one, the author clearly overexposed a scene with trucks, saying that he applied an ETTR technique, when he clearly did not – if he did not overexpose his image to the point of no recovery, he would have been able to get the underexposed and ETTR image to match perfectly in highlights. But he clearly lost his highlights, which is NOT what ETTR is about as a technique!
The second link is clearly showing an underexposed histogram as an ETTL example. All I can say is, if the author pushed that exposure to the right, he would have ended up with a better image, period. These are the words of the author that describes ETTL: “Exposing to the left by, for instance, underexposing by a stop or stop and a half will preserve highlights, they say.” Whoops, I think he just described ETTR. If you end up with an exposure that preserves highlights better, it is ETTR, not ETTL.
I am sorry, but both links are not from authoritative sources that have a history of scientifically accurate material, so neither are proof of anything useful, especially in these examples.
ETTR is a technique. ETTL is underexposure. I am sorry, but there is no other way to phrase it. If you disagree, please provide a histogram that clearly demonstrates ETTL, with your arguments that explain its use and I am happy to discuss this further.
Nasim,
Only time for a short reply I’m afraid as I’m running through the new Z50’s functions here. So far it’s exactly what I was looking for – a high quality D5600. Great as a travel body I hope. AF, VR, eye-detect all working well with adapted lenses too. Sensor seems similar to D500. Bargain price of £990 here in the uk with the 16-50 and FTZ.
Anyway, referring to your concluding note: ‘ETTL is underexposure’. Again, no I strongly disagree with this statement. Underexposure is the small adjustment you may often require when your meter is not giving you the result you want. It is always a reduction in exposure but could be applied to any sort of exposure distribution. It may be applied when you just think the overall picture seems a bit bright, or when you find the highlights are clipping. In the former case your resultant histogram may be anywhere, you are not interested in the boundaries. In the case of adjusting for highlights, you will be typically interested in the right boundary. In contrast ETTL is a change in the exposure your meter is giving you, which could be either an increase or decrease in exposure depending on your scene and your metering, in order to optimise the exposure of subjects toward the left side of the histogram (i.e. typically a dark scene). When the critical and majority of the subject is dark and you want it to remain dark, ETTL is used to ensure the dark information is all gathered (nothing lost to the left), but also the ISO is not unecessarily boosted which would cause an increase in noise and loss in dynamic range in those dark areas. So in ETTL you adjust your exposure one way or the other with close observation of what is happening on the left side of your histogram since that is where all the data is likely to be. In underexposure, you may not pay any attention at all to the either side of the histogram since it is most likely to be either minor adjustments.
There are 100s of millions of ETTL example pictures all over the world. Typically they will be of a dark scene with the majority, if not all, of the histogram on the left side. Think of night-scenes, moody fashion shoots, ASTRO work etc. Typically, if you use matrix metering your camera will overexpose the scene and you will get horrible gray noisy picture when you want darker and richer. Hence you either have to underexpose or you may have identified a highlight element (like a small moon in a night sky for example) to meter from and you may then need to move the exposure either way depending on what is happening in the critical dark areas.
This is the case for ETTR and ETTL as defined for decades before digital sensors even existed. In the world of digital sensors, it is pointed out that noise in highlights is less problematic than that in shadows, but this is exactly why you should not use ETTR when the shadow details are the critical and majority of the picture. ETTL will get the most out of the dark areas without introducing excessive noise and losing dynamic range. There are claims that sensors are ISO invariant regarding nosie (although I’ve never found that to be the case myself), but there aren’t any sensors that are invariant to dynamic range which decreases almost stop for stop with ISO, so applying ETTR to a dark scene will greatly increase the noise and reduce the tonal quality of the final picture.
Anyway, let’s not lose any sleep over this one. I need to see how the Z50 does with some birds in flight. No chance for ETTR there I’m afraid.
So much nonsense contributed by someone who is clearly terminally confused about digital exposure, what the histogram is for and how to put it to best use. I have never read such a muddled bunch of gobbledegook in all my life. A completely inverted version of reality and best practice.
“ETTL is underexposure’. Again, no I strongly disagree with this statement. Underexposure is the small adjustment you may often require when your meter is not giving you the result you want.”
In every case the result you want is maximum data and in every case optimal exposure is that exposure which puts the histogram as far to the right as possible for any scene, light or dark. Any interpretation and adjustment of that data for creative reasons belongs in the digital darkroom, not in the camera.
“So in ETTL you adjust your exposure one way or the other with close observation of what is happening on the left side of your histogram since that is where all the data is likely to be. ”
What absolute nonsense. Digital exposure is linear and the left side of the histogram always contains the least data. Not only that but the reduction is exponential so pushing the histogram to the left has disastrous consequences – loss of data, increased noise and risk of artefacts when editing depleted data.
This and other comments about ‘centring the histogram’, etc, display a profound ignorance of all aspects of digital exposure which when wedded to outdated dogma appropriate to film, are both dangerous and misleading and can serve only to confuse and mislead new photographers trying to learn digital exposure from first principles.
Even when Nasim tried politely to put you on the right path you challenge and deny his sound advice in favour of your own version of reality. This tripe should be deleted in the interests of all PL readers.
“Anyway, let’s not lose any sleep over this one. ”
Yes, we should be losing sleep over this one. It’s the stuff of competent photographers’ nightmares.
Oh, and ETTR is applicable to birds in flight too (albeit not perfection).
Burghclerebilly
If your exposure is already ‘ideal’ why on earth would you want to increase it? 🤪
Well written article.
I had briefly heard of ETTR before but wasn’t 100% about what it was, this article has definitely cleared up what ETTR is and how to use it.
I look forward to trying it out.
there’s no ETTL,because all three histogram histogram are ETTR in my definition:)
I would just emphasize (it was pointed out in the article) that much depends on where the main subject of the photo lies in the exposure range of scene you are trying to capture. The subject being brightly lit by the sun and the subject in shadow could and would change your strategy. The former gives much latitude to bring the subject exposure down to help with highlights, the latter would risk moving the subject into a very dark place where recovery will be compromised (noise). In both scenes, the actual dynamic range of the scenes are identical, but the main subject’s place in that range determines exposure strategy.
There is no over all perfect answer other than taking great care in planning the shot for the best lighting scenario.
Exactly! You meter and expose the subject or the part of the scenery, not the whole image area. Whereas it would be desirable to always capture the whole dynamic range, the information resolution in dark areas is always much lower than in bright areas. 50% of the image information is in the most left part, while only 3% is in the lowest right part of the same size. Considered that it is a must that all information of the image should gather to the left of the histogram. BUT and I stress that very much: If you loose data on the very left side of the histogram, you loose a lot of data. (If you do leave space, you loose a lot though). So that risk is a big drawback. Either the risk of clipping or the risk of more shadow noise.
Again I call for RGB-histograms, true 12 or 14 bit histograms, not 8-bit JPG ones. That would us spare a lot of troubles. Exact image information, instead of a guessing of how much to “overexpose”. Come on Nikon, Canon, Sony et al. Why wouldn’t you finally implement it?
Sorry, correction. I wrote: If you loose data on the very left side of the histogram, you loose a lot of data. (If you do leave space, you loose a lot though). It should read: …(If you leave space unused you miss the chance of gathering much more information).
In real life we have to guess. I discovered that Nikon DSLRs show clipping parts on the back LCD, while the RAW-histogram in post processing shows all information gathered. It is about 1/3 to 2/3 stops on the safe side.
Hello Jan,
With all respect and polite intention, the word you spell as loose is correctly spelled as lose. I thought you might like to know. Cheers! :)
Thanks, Elaine. I am not native English speaking and sometimes such stupid errors happen. Sorry.
Jan
“If you leave space unused you miss the chance of gathering much more information).”
With respect, this is not so. You seem to have things back to front.
Maybe I am misunderstanding you but to be clear, the right side of the histogram contains the majority of the data. If the right-most stop contains 256 levels, each stop down on the histogram contains 50% less data than the one before. 256-128-64-32-16-8. The left side of the histogram contains very little data which is why it is so important to keep to the right. As long as the exposure is pushhed to the right without clipping, unused space on the left is immaterial.
For example, to correctly expose a black cat in a coal cellar, you would need to ETTR as far to the right as possible. This would likely produce a very pale grey cat – containing maximum data – in the back of the camera. You would then adjust the brightness of the cat in post to produce a highly detailed black cat containing every subtle shade in its darkest tones.
Exposing the cat to ‘look right’ (black) in the back of the camera would be to greatly underexpose the cat resulting in reduced detail and unnecessary noise.
Jan, true RAW histograms is something we have been asking for a while now. The AD converter has all the data, so it is just a matter of writing a RAW histogram as part of the header in the RAW file. I don’t know why it is so difficult for manufacturers to implement it. It would completely eliminate the guesswork and we could always look at the rightmost side of the histogram to see if anything is blowing out. I would love to see a true RGB histogram though, not just a generic black and white version.
Difficult lighting is difficult, while good lighting is forgives many sins. One has to know one’s camera, glass and what they will do at various exposure triangle settings. Bracketing can be good insurance in some bad situations, either for alterntive choices or for layering in post. I have to say the settings for that very interesting huntsman portrait surprises me. Given apparently decent lighting: why ISO1000 at f/2.8 and 1/500? Seems like toning down ISO and/or aperture at a completely manageable 1/200 (assuming handheld) could have spared noise versus sky issues? (I personally might have preferred smaller aperture for more DOF detailing the foregrounded pelts.)
Albin, I am glad you brought it out, because I was wondering if anyone else is going to notice the exposure values on that photo. A quick background: I was shooting live action and I needed to have fast enough shutter speed to freeze motion. Then I saw this guy walking by, asked if I could take his photo and snapped a couple of shots without changing my settings. This is how it ended up being ISO 1000.
Thanks for the explanation. Without context often hard to tell if a situation was catch as catch can or a posed set up.
Thank you!
I also read the article you mentioned about ETTL which left me dumbfounded and confused.
I’ve worked in video and still for 40 years and the ETTL logic makes zero sense to me.
Preserving detail in shadows is crutial to avoid adding noise in post…and your assessment of exposing the subject is 100% on point.
Thank you for clarifying and educating the readers.
Cheers
Yes, ETTL is total nonsense.
It makes zero sense to you because you understand exposure.
Simples.
Hi Nasim,
I totally agree with your article. Many thanks as it gives me a “known author” now that helps me to speak with more conviction to others.
Have a nice day!
Nicolas
Ethic Wildlife Photogfrapher
Hi Nasim,
My previous understanding of what ETTR is was rather overthrown by this article and I now thought I understood it much better. That was until I read the exchanges between you and Burghclerebilly, which threw me into complete confusion. So I am going to write what I think you are meaning in very layman’s terms, and perhaps you can correct me where I go wrong.
The ultimate goal of correct exposure is to preserve the detail in highlights and shadows as much as possible, depending on the photographer’s goal for his photo. ETTR is a technique by which you meter your picture some degree brighter (slightly overexposed) than center in order to push your data (as expressed by the histogram) closer to the right side stopping short of having a white bar climbing up the right hand side of the histogram, which means complete data loss in your whites. In some cases where you prioritize shadow detail, you then would rather push the histogram to some degree left of center by underexposing your photo a bit, stopping short of having a big black blob on the left of your histogram. So I conclude that ETTR is a technique that is all about the histogram which aims to tell you how much raw data you photo has in it, in order to judge whether you have maximized your exposure with the most data that you can gather at either extreme, brights and darks. If I am not correct, which I suspect is the case, what am I not understanding?
Hi,
I would rather say that ETTR means in all cases you take your picture as bright as possible without loss of any highlight you think relevant to the photograph. You never ‘push the data to the left’, except if you mean by that that some important highlights would be clipped if the histogram were more to the right (which implies the data are ‘maximally’ pushed to the right). The picture may be (globally) underexposed thus, but it is easier to recover the shadows than the highlights.
If you prioritize shadow details, you still want them as bright as possible; there is no point in getting the minimal amount of light that doesn’t clip them (i.e. pushing to the left), you rather take the maximal amount of light from the shadow that does not harm any relevant part of the image
.
If, by this technique, you cannot avoid clipping some shadows, or if they are too noisy to your taste, then it means the dynamic range of the scene is too wide to record in a single picture; you can then choose to sacrifice some highlights or some shadows, or you can stack different exposures.
Well, to sum it up (probably already said above by Nasim or someone else), it is called ‘to the right’ because the picture is made as bright as possible: doing less would harm its quality.
Another way of describing ETTR:
you take a picture with some settings and check the result/the histogram;
– if overexposed (clipping important highlights), then while it is, modify the settings to expose less and retake the picture; the result is the brightest ‘clean’ picture you could get;
– if underexposed (the brightest highlights not being on the rightmost part of the histogram or beyond), then while it is, modify the settings to expose more and retake the picture; the result is also the brightest ‘clean’ picture you could get.
At not moment do you, in this process, check the shadows. You could, to balance the importance of the highlights. But even then it is always better to push them as far to the right as possible without harming the highlights you still want to retain.
Elaine, please ignore the comments and focus on the article and what it says. The first part of your summary is correct about ETTR and pushing your exposure to the right without losing data. Don’t worry about the part “in some cases where you prioritize shadow detail”. Just make your exposure as bright as possible each time when possible. If the image is too dark, there is simply too much dynamic range – just bracket your shots.
Great article. I get so frustrated with people who say they always underexpose.
It almost always comes down to some youtuber telling them to shoot dark and fix the rest in post, and they never believe me when I tell them you should do it the other way.
Joshua, glad you found the article useful. Unfortunately, there is a lot of misinformation out there, which can lead to wrong conclusions.
Now I’m totally confused, thanks! is it ETTR or ETTL?
The physics is crystal clear to me, but the definitions and supporting statements are contradictory. Somehow reminds me of Macro vs Micro definitions by Nikon and Canon. Does ETTR mean brighter sooc image than ETTL or the other way around?
Rashad, ETTR is the ONLY good technique for proper exposure on a digital camera. Don’t worry about other terminology and contradictions, because they will only confuse you. If there is anything in the article that does not make sense or looks confusing, please let me know.
The confusions some get, me too, are the result of the arguing about the terms ETTL and ETTR. Nasim’s article and his answers in the comment section are correct. But that does not necessarily mean, the other postings are all incorrect.
It is all about collecting as much information as possible in your RAW file. It is NOT about the right exposure of the final image. This is done in post processing.
I suggest we skip the terms ETTL and ETTR and we only take a look at the true RGB-histogram. And we should actually look at the colours and not the white histogram.
Remember: the more photons get to the sensor, the less noise is in the image. And remember: On the right side of the histogram is much much more information storable to the RAW file than on the left.
Consider a sensor is able to record the whole dynamic range perfectly with a dynamic range of 1000 stops (instead of only 14) we would still expose as far as possible to the right of the histogram. Just because the more information is shifted to the right side of the histogram the better shadow recovery works. We’d never have overblowns and shadow recovery would be a dream. We could catch almost all information at any time. And we would never have to bracket.
In highly dynamic ranged scenes the advantage of exposing just before clipping diminishes.
In the real world sensors have around 14 stops dynamic range and shadow recovery is therefore not that easy. Some bright parts of a scenery might be so bright that the distance to the dark parts is very big (a huge dynamic range like the shadow of trees in the foreground and a white building’s façade or snow covered mountains in the mid day sun in the background). We still would expose such as the histogram is shifted to the right side without clipping on the right. But the advantage to recover shadows is mostly gone due to the very high dynamic range.
So we either expose for the subject and do the same as described above, only this time for parts of the image or we bracket. If bracketing is not possible we have to live with overblowns in other parts of the image or some dark areas do not get enough light and are noisy. (Or use a powerful flash to lighten up your subject).
Conclusion, if you shoot RAW: Always expose your image so far to the right of the histogram as possible. Do not mind the possible overexposed look of your image, just turn down the exposure in post processing. Your benefit: The recovery of dark areas with less noise. Your drawback: One step in post processing and maybe a bad overblown look on the rear LCD of your camera.
Cheers! -jan
Good answer, but at the risk of nit picking….
“It is all about collecting as much information as possible in your RAW file. It is NOT about the right exposure of the final image. This is done in post processing.”
With respect, exposure cannot be fixed in post processing. The image brightness can be adjusted up or down but this does not change the original exposure. If it did, there would be no need for ETTR exposure.
Very well explained. Thank you, Nasim!
Thanks for posting this, I thought I was going mad! The right hand side of the histogram area is some much more efficient at capturing data, to deliberately underexpose the image is madness in any digital camera. I’m convinced those who advocate exposing to the left have little knowledge of how digital sensors work, incidentally this is not opinion it is measurable fact!
Is it correct to say that ETTR should only be done when you are in manual ISO mode (or in sufficient light that even in auto ISO it’s staying at base value)? It seems like there could be diminished returns if as you increase exposure, ISO also goes up, in terms of noise.
ISO settings should at any time be as low as possible but on the standard ISO value (e.g. 60 or 100). If you choose AUTO-ISO it will work against your try to overexpose so that the histogram is filled to the clipping border at the right side. But what you could do then is using the exposure compensation and dial +1/3 or +2/3 depending on the scene and what the histogram says.
But in real life, I wouldn’t bother that much. In fact, I do not bother at all most of the times. About D800E and D4 I can tell for sure that they leave space unused on the right of the histogram. You won’t see it if you check the JPG-histogram on the LCD of the camera. That might show that you are already clipping on the right side. But in post processing it turns out that you can still recover about 1/3 to 2/3 stops of the highlights. This margin helps a lot in scenes where bright(er) parts tend to get overexposed.
Since we do NOT have true 12 or 14bit RGB-histograms it is best to know your camera, how it takes pictures. Take sample shots and compare them. In highly contrasted scenes it won’t help much.
But before one cares about ETTR there are plenty of other things to do to improve. It is one of the least important things I’d say. It is geeky. It is like getting the most out of your audio recordings to tapes some 20 years ago when you would go as high as possible with your levels.
Cheers! -jan
Yes, I agree with Jan,
Firstly, the terminology is irrelevant when you are talking about digital sensor optimisation. Whether you want to call it ETTR, ETTL, dynamic range optimisation, chiaroscuro, zone-method etc. They all involve moving the exposure one way or the other in order to optimise the dynamic range and noise characteristics by looking at the histogram and considering the subject, important background, and unimportant background elements. And the starting point is to understand that overall noise is minimised and dynamic range maximised at low ISOs, as Photons to Photos cleary shows. The D850/Z7 have ISO 64 for a reason!
Moreover, if such techniques are to be applied to optimise digital characteristics they should only ever be the 4th or 5th exposure consideration after the photographic considerations of (1) the appropriate shutter speed (camera shake/motion blur) and aperture (depth of field/subject separation) for your subject; This applies even in a studio situation where you can control the light due to the modification options of the inverse square law (subject separation) (2) The stability of the lighting conditions (risk of clipping); (3) The optical characteristics. You may not want to apply a wider aperture if that introduces vignetting, chromatic aberration, and you may not want to stop-down if it could introduce diffraction. (4) The output medium. If you want to optimise the DR (achieve the 12-14 stops that the base ISO offers you), you will not be able to see that on a typically monitor screen. However, the difference in DR and contrast between printing on for example canvas and premium glossy paper are large (probably 2-3 stops).
Hence ETTR, ETTL etc used purely to optimise digital sensor performance must be seen as an extremely niche option, and if ever used would not be expected to lead to a large change in exposure given all the other photographic expsosure issues, which surely are more important.
Correct exposure is always defined at base ISO.
Sometimes (or often if you shoot active subjects in low light!) getting the shot inevitably has to compromise ‘ideal exposure’ to some degree. If you really need a particular shutter speed/aperture combination and this leads to some underexposure then so be it – we have to increase the gain on the sensor by increasing ISO. But you can still ‘minimise the damage’ by exposing as far to the right as possible in the first place. However, sensor and noise reduction technology are now so good that at modest levels image degradation is minimal.
I have also found that the color red gets blown out when taking an image that has a lot of red in it, i.e. red flowers etc.
In those cases I also like to look at the separate color histograms just to make sure the red channel isn’t blown out. It is very difficult (if not impossible) to bring back the red flower petals when that happens.
Also, by changing the metering in the camera, that will help for those tricky shots too.
Mark, good to hear from you sir – warmest regards to Emily!
That’s a good point about overexposing a particular channel like red, which is easy to do when shooting flowers or anything that contains a lot of that color. An RGB histogram in such cases can be very helpful to make sure that the channel is preserved as much as possible…
Great article. One quibble, though, which is that not all “film” behaved the same way. For negative film, particularly silver-based B&W, yes, there was a great tolerance for overexposure. But for positive (i.e., slide) film, it was more like digital, with very little tolerance for overexposure. So when I was shooting negatives, I would expose for the shadows and let the highlights fall where they might, but when I was shooting slides, I would expose for the highlights and let the shadows fall where they might (and with the limited dynamic range of slide film, that could be pretty dark). But, as you point out, both those methods are really “ETTR,” as both are aimed at achieving as much exposure as possible while preserving highlights.
But then there was always the wonderful Ted Orland quip: “Expose for the secrets; develop for the surprises!”
Love that quote, thanks for sharing!
Barry, thanks for pointing it out. I didn’t mean to generalize all film, and I specifically had “depending on film type” comment in my article. To avoid further confusion, I slightly modified the text to point out that I was referring to negative film.
I thought the explanation given is accurate and clear.
Not sure why so many seem so confused.
IMO it is important that beginners understand that there is (often) a big difference when exposing for a jpeg image vs exposing for a raw file.
In fact that’s the first thing I ask myself when shooting an image:
Am I looking to enjoy this SOOC or am I going to process it?
On occasion I will shot a couple for each file type. ( I shoot raw + jpeg)
I’ll take one that I think “looks nice” and then one where I will saturate the sensor as much as I can.
I’ve read a lot of confusing ETTR articles; this one will make the topic quite digestible for many people.
Love this site !
Thank you for your feedback David, glad you enjoyed the article!
I did not think that was very helpful at all. You often confused exposure concepts. Your film comments did not take into consideration transparency (positive) output or print film (negative). Overexpose transparencies, even slightly, at your peril. The aim with digital photography is to expose CORRECTLY. What is needed for one image can be vastly different from another. Most photographers understand this and the concept of exposure compensation. They do not need concepts like ETTL. If such a concept exists as distinct from over exposure, then ETTL or ETTC are just as legitimate depending on the subject. Be careful recommending in this day and age to use what you term base ISO. Photographers need to seek an appropriate balance between aperture, shutter speed and ISO for the subject. As a Nikon devotee, I am sure you are aware of how easily this can be set up.
In conclusion I felt you made some simple concepts confusing and pedantic.
David, my comments on film are very generic and relate to some particular film types that have much more exposure latitude in the highlights than in the shadows. They wouldn’t apply to things like slide film, where dynamic range is limited and overexposure is not tolerated. I did not want to add too much detail to all this and mention specific film types, as the idea was simply to mention differences in how one could expose for some types of film vs digital. These comments weren’t meant to generalize all film.
In regards to digital exposure, ETTR makes a lot of sense if you understand how a digital sensor works. I’m not going to reiterate what has already been said, but an ideal exposure for digital is not just about using the exposure compensation button, or understanding the relationship between exposure variables – it is about saturating pixels to the point where data can be processed and recovered without much penalty. A sensor is not sensitive to light like film is, so even the concept of ISO is very different compared to film. Base ISO is typically where image sensors perform the best with the widest possible DR, so of course I’m going to recommend to stick to it whenever possible. Are there exceptions to these recommendations? Of course – I devoted a whole section to this in the article to show that.
ETTR is very simple to understand. All you have to remember is that if you can make your image as bright as possible without blowing out the highlights, you will get better results in post. This is a proven methodology and it works.
It is a shame that Nikon and Canon, after all the years of experience in the field, cannot provide an auto exposure metering mode to recognise difficult scenes and adjust accordingly. I guess the best policy is to crank the exposure compensation setting to +0.5 or +1ev to nudge the camera’s exposure to the right. I see very little if any noise in my images since plumping for the D810, very different in that respect to the APS-C’s I had been using. Of course, the software for post processing has also improved so much that a lot of these images are not degraded as they may have been a few years ago. I recall using slide film years ago, where highlights simply left clear areas of celluloid garnering no image information at all, exposure being highly critical to avoid wiping out detail, while underexposing left muddy (we call it noise now) areas which detracted from the result – but there was not much lattitude for fixing an incorrect exposure. My SLR at the time had two buttons over on the left side near the lens mount, You could meter a scene, press one to lock exposure, then recompose and shoot. The other button the same, except that you had to keep it depressed until you took the shot. That camera also had exposure compensation available so I learned a lot from using it. A 25 year break from photography, and I came back to it via DSLR’s. I was fully expecting, after a quarter of a century, that the camera manufacturers would have sorted this problem out – only to find the ability of in-camera metering, though vastly better in many ways, still stumbles on tricky images. Goes to show you, 40 years after they put a man on the moon, we’re still not quite there yet! Great analysis as usual Nasim, At least these days we don’t have to wait for our film to be developed, we can be more dynamic in our quest to discover how to fix such problems. I am also glad the cost of doing this kind of experimenting is much lower now – no film, no processing. Today’s photographers have it so much better, I do miss film though, I learned so much when using it. It made you think a lot more – digital can make you a little slapdash, with the ‘fix it in post’ approach being a little too prevelant – I am guilty of that too, but this article makes me remember so much about those tricky shots when using film, it is well worth the effort. Your readers should now go off and deliberately choose shots which have these issues, to perfect their technique in dealing with them. That is the fun part of all this, after all!
simply a huge thanks nasim!!! simple, to the point, and explaining why!!! such a confusing topic that one could endlessly misunderstand because of not being told the whole theory!!! you, and photography life, is my most trusted go-to, to be able to fully understand what the topic happens to be!!! thank you ever so much!!!
very well explained . I often use bracketing to get as far to the right as possible to avoid the noise in shadows . Generally only one file is used although there are times some lost highlights and shadows may used from the other two files. Using raw capture also increases the possibility of recovering slightly blown highlights . Mirrorless cameras with live histograms in the EVF are a god-send for getting exposure correct with one click
Little bit of history — in the early days of digital, it was often suggested to expose more to the left so there is less chance of blown out the highlights that cannot be recovered; as mentioned above . There are still a number of older “do not dos” and “must dos” that are no longer applicable to today’s amazing equipment . My first pro quality camera (nikon D1) that “featured a 2.7-megapixel image sensor, 4.5-frames-per-second continuous shooting” — but that was only with jpg LOL. That camera was over Au$2000!!
Another great article from you — many thanks for your time
There is something to consider: Some days I shot some performers of a classical concert with the D4 in low light (not while playing, of course) in the range of about 5000 to 12800 ISO. If you take quickly some pictures in a row, there can be some inconsistency with the exposures e.g. in low light. Some of the images were a little overexposed, some a little underexposed. The extra space to the left which could be used for ETTR was used of the overexposed shots and could be fixed in post processing. So this is also a safety margin left by Nikon (or Canon, but I do not know about that for sure).
Thanks ! I was speaking to a photographer other day about this and he said he exposes for the shadows ..so I got nicely confused but this helped clear it up. I try to expose to the bright (as I call it) but the blinkies always throw me off and I worry I overexposed (practice practice) but it definitely makes sense to make image bright and not have noise in the shadows.