Most recommendations for ETTR (exposing to the right) require you to use the histogram and “blinkies” on your camera to judge overexposure. And while this method works fairly well and has plenty of benefits, it isn’t flawless. Here’s an alternative method involving spot metering, which works better in many cases.
Table of Contents
What Is ETTR?
ETTR is a method of exposing photos which involves capturing as much light as possible, without blowing out any important areas of an image. We’ve written about it before. It is also known as optimal digital exposure.
Some photographers incorrectly think that ETTR involves taking photos that “look too bright” and then darkening them in post-processing. This isn’t always the case, though. Many photos which are properly exposed to the right will look dark out of camera. That’s because a central tenet of ETTR is to avoid overexposing critical highlight detail.
The following image is exposed to the right; in other words, it is captures as much light as possible without any overexposure:
But so is this image, since it also is the brightest possible exposure that doesn’t blow out any important highlights (those clouds are just barely recoverable):
It’s critical to understand why both cases are proper ETTR if you want to understand optimal digital exposure – including how to implement the spot metering technique in this article. (If it’s still not clear why both samples above are ETTR, check out Nasim’s article on the myth of exposing to the left).
Issues with the Usual ETTR Technique
Exposing to the right may seem straightforward – you’re just capturing as much light as possible without blowing out any important details – but finding that balance in practice isn’t always easy.
For example, if the sun is in your photo, it often will be blown out, with no detail in any of the color channels. That’s not a problem, though; what you’re really trying to avoid with ETTR is blowing out important highlight details. So long as you don’t mind if the sun is completely white in your photo, it’s not relevant to this discussion – except that it affects your histogram and makes the rest of your photo much more difficult to judge.
The following histogram may look overexposed, with a spike on the right edge:
But it really isn’t, because that spike corresponds to the sun in this properly exposed image:
Since most photographers judge ETTR based on their camera’s histogram, this presents a bit of a problem. Your histogram may look overexposed, yet nothing important in the image is actually blown out.
That’s why a lot of photographers recommend looking at your in-camera “blinkies” as well – those little black/white flashing indicators to pinpoint where overexposure is occurring.
But these also are an imperfect solution. As you have probably realized if you use blinkies often, they’re generally too sensitive to what counts as “overexposure.” Often, bright areas are recoverable even when the blinkies say they’re blown out. Some recent cameras let you fine-tune the sensitivity level to be stricter, but many do not.
Finally, a big issue with both blinkies and histograms is that they depend on your JPEG picture control settings, even when you’re shooting RAW (which, of course, you should be doing). For example, as you use progressively higher contrast JPEG settings, your histogram and blinkies will show overexposure sooner and sooner – even though the underlying RAW photo isn’t changing.
You can get around this issue to some degree by setting ultra-low contrast and “flat” picture controls – but even then, unless you’re at a specific white balance setting (known as UniWB), the histogram still won’t match that of your RAW photo!
In the end, fully optimizing your in-camera histogram is not an easy process. It involves setting your JPEGs to have ultra-low contrast, as well as the maximally green “tint” value, leading to JPEG previews that look almost nothing like how your final image will appear. (Admittedly, you can mitigate this somewhat – and even potentially extend the dynamic range of your sensor – by using a CC30 or CC40 magenta filter on the front of your lens. But I suspect I could count the number of photographers who do this regularly on one hand.)
Instead – though it has issues of its own – the ETTR method I’m about to describe tends to be more precise than the usual histogram and blinkies methods, without the same JPEG preview compromises. Depending on your style of photography, you may find it preferable.
ETTR via Spot Metering
To implement my preferred ETTR technique, you first need to switch to spot metering. After that, you need to spot meter on the brightest part of your photo and add a significant amount of positive exposure compensation. The key is to figure out how much positive exposure compensation you can get away with, while still being able to recover all highlight details in post-processing. This depends on your particular camera’s sensor characteristics.
Here’s the exact process:
- Spot meter on the brightest part of your scene. It may take a few moments to figure out what that is (especially if there are a few different bright regions, and you’re not sure which is brightest), but you’ll get faster at this with practice.
- Since your camera is trying to place those highlights at middle gray, you need to expose several stops brighter than what the meter is telling you. The specific +EV value is something you can find pretty easily for your camera (I’ll show you how to do that in a moment), but something in the +2 to +3 EV range is about typical.
- Regardless of what +EV value it is, you’ll use the same one every time. Take the photo, and post-process as you normally would for an ETTR shot.
The benefit of this method is its consistency. Once you pin down how much highlight recovery your camera can do, you’ll be able to use this technique on a wide variety of scenes – from low to high contrast – and achieve an optimal exposure.
With my Nikon D800e, for example, I figured out that I consistently could recover highlight information when it was 2.7 stops above middle gray (i.e., +2 2/3 EV). So, my process with that camera was to spot meter on the brightest highlight in my photo and add 2.7 stops of exposure compensation (or boost my shutter speed 2.7 stops in manual mode). And that’s all there is to it! I think this technique is pretty easy in practice, even if it takes a moment to describe here.
Note, too, that this method does not require you to pick certain JPEG settings or a specific white balance in order to work properly. That’s because none of the JPEG picture controls alter how your camera’s meter works (aside from Active D-Lighting on Nikon cameras, which you should always turn off). That’s a nice benefit and allows you more flexibility in picking your JPEG preview settings.
Real-World Example Photo
Take a look at the sample below. The brightest region here is pretty clearly in the center of a cloud on the right-hand side:
With spot metering selected, I moved my focus point over the center of the cloud. (I did this in live view, which I typically use for landscape photography, but it works when shooting through the viewfinder as well.) The camera recommended an exposure that looked like this:
Of course, this is too dark, since the camera placed the brightest highlight in my image at middle gray. However, I knew from prior tests with my Nikon D800e that I could recover 2.7 stops of exposure beyond middle gray. So, I boosted my exposure +2.7 stops, and my out-of-camera RAW image looked like this:
This is the proper ETTR exposure. Although it may seem overexposed at first glance, here is this photo’s RAW histogram:
As you can see, although the highlight detail is right next to the edge, none of it is actually touching. As a result, all the highlight details are recoverable in this image. When I decrease the “highlights” slider in Lightroom and do my usual post-processing, here’s how the final image appears:
Success! Not only is this image sharp, with high image quality in the traditional sense, but it also benefits in noise and dynamic range thanks to my optimal ETTR exposure. And none of the highlights are blown out, either.
Finding Your Camera’s Highlight Recovery Capability
The only missing point at the moment is to figure out the amount of highlight recovery you can expect on your camera. In the case of my D800e, it was 2.7 stops, but anything in the 2 to 4 stop range is worth testing just to see how it looks.
Testing for highlight recovery is fairly easy.
- Find or set up a scene with even lighting, where the brightest item has a modest amount of texture and some color – for example, a plant under diffused studio lights.
- Spot meter on the brightest part of your subject and take a reference photo at the camera’s recommended settings.
- Increase your exposure (by using a longer shutter speed) and take a series of photos from +2 EV to +4 EV brighter than the reference photo, in 1/3 increments, for a total of seven test images.
- Open the photos in your post-processing software, and try to recover them to match the reference photo.
- If the color shifts significantly or any highlights turn gray when you recover the image, that means it’s overexposed. (Though make sure your white balance setting is the uniform across the images.)
- The brightest photo which is not overexposed represents your highlight recovery range. In the case of my D800e, it was the image at +2.7 stops.
- Test out this +EV with different subjects – especially the types of subjects you commonly photograph – to make sure you get consistently recoverable results with this value.
To make things even clearer, here’s the exact process with the Nikon D780. First, this is the reference photo of my scene. I metered in the center of the image on the brightest part of the leaf:
Then the seven test images:
When I recovered those seven images, the first three looked perfect, and the fourth image (+3.0 EV) only had very slight regions of overexposure. The final three images looked quite bad, with significant areas of blown highlights. Here, for example, is the recovered image at +4 EV:
By comparison, here are extreme crops at +2.3, +2.7, and +3 EV (in that order from left to right):
To me, the first two images have proper colors and appear indistinguishable. As for the third image (the one at +3 EV), the overexposure is admittedly not huge, but it does exist. If you look closely at the edge of the leaf near the center of the image, you can probably tell that it is quite a bit duller than the previous two. You will probably find it easier to spot this difference if you click the images to see larger previews.
Since even a slight color shift is enough to disqualify the photo, the real-world highlight recovery range on the D780 is about the same as that of the D800e: 2.7 stops. If I had chosen a subject with practically no texture at all, like a ColorChecker Passport, I perhaps could have recovered the +3.0 or maybe even the +3.3 EV image. But this test is meant to give you a practical guide for real-world photography, so a leaf under gentle light is a better sample subject than a flat color swatch.
Thanks to this test, when I’m using the D780, I now know that I just need to spot meter on the brightest part of my frame, add +2.7 stops of exposure compensation, and take the photo. It’s a quick and easy way to expose to the right.
Drawbacks of This Method
As useful and easy-to-implement as this method can be, it isn’t perfect. One of the main issues is that it simply adds some more time to the process of photography. That’s especially true because it isn’t always immediately obvious which part of your photo is the brightest, and figuring out the answer (by scanning your spot meter across the frame) can take some time in the field. So, I really only recommend this method if you’re shooting a nonmoving subject from a tripod, such as landscape or architecture photography.
On top of that, the camera’s implementation of spot metering itself can cause some problems. Specifically, spot metering doesn’t measure an infinitesimally small point; instead, it averages readings from a relatively small box, about the size of a focusing point. If your subject has very strong textures, such as grains of sand up close, this average reading may not actually be close to the brightest highlights in your photo. So, you could end up overexposing by accident. (The same is true if the brightest element is smaller in size than your spot metering point, like a thin outline around a backlit subject.)
That’s why this method isn’t always ideal, and should be combined with the histogram/blinkies method in difficult cases. Still, for common situations – especially landscape photography with a bright sky – I’ve found it easier to get consistent ETTR exposures with this method than any other technique.
When in doubt, too, you can always darken the photo slightly and go with a safer value for your exposure compensation – say, +2.3 stops rather than +2.7.
NIKON D800E + 105mm f/2.8 @ 105mm, ISO 100, 1/40, f/11.0
NIKON D800E + 35mm f/1.8 @ 35mm, ISO 100, 1/25, f/11.0
NIKON D800E + 20mm f/1.8 @ 20mm, ISO 100, 1/25, f/16.0
In response to a comment to this article, here are the same three images with a red box to indicate where I spot metered:
Conclusion
If you’ve found it difficult to achieve consistent results with ETTR, perhaps this spot metering technique will help you out.
Personally, this is my current go-to method of ETTR for landscape photography, and I now only use the histogram/blinkies as supplementary guides for more difficult exposures. The spot-metering method of ETTR is more precise and accurate than trying to gauge the histogram/blinkies, at least for most subjects. It also means you don’t have to worry about using an ultra-flat Picture Control style or UniWB, so the preview on your camera now can look more like the final image.
That’s not to say this is the perfect method, nor is it right for everyone. Even if it is useful for you, keep in mind that ETTR in general is pretty far down the list of things you should worry about as a photographer, and this technique is even more esoteric than regular ETTR. It definitely plays second-fiddle (or third, or fourth, etc.) to things like light, subject, and composition.
But for those of you who are trying to get every bit of image quality out of your camera, hopefully you found this essay to be useful and informative! If you have any questions, please let me know below.
If i shall add – to get precise ETTR exposure, besides spot metering, shoot in flat color profile if it’s available on your camera.
The color profile doesn’t affect the raws, but, the histogram is based on a jpeg generated as a preview, not the raw file itself. If you shot in other color profiles which enhances the jpeg in some way (like more contrast), it’ll seem like you clipped highlights our shadows of both, when actually you didn’t.
If the histogram was read from a flat profile image, indirectly you’ll get a more accurate histogram reading because it is the least contrasty colour profile.
Obviously, you didn’t read the article, which states:
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Finally, a big issue with both blinkies and histograms is that they depend on your JPEG picture control settings, even when you’re shooting RAW (which, of course, you should be doing). For example, as you use progressively higher contrast JPEG settings, your histogram and blinkies will show overexposure sooner and sooner – even though the underlying RAW photo isn’t changing.
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You can get around this issue to some degree by setting ultra-low contrast and “flat” picture controls – but even then, unless you’re at a specific white balance setting (known as UniWB), the histogram still won’t match that of your RAW photo!
END of QUOTE
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Furthermore, you have confused color profile with picture control: the two are completely different.
“ETTR is a method of exposing photos which involves capturing as much light as possible, without blowing out any important areas of an image.” In other words, ETTR is equal to perfect exposure and thus neither “to the right” nor “to the left”. So instead of thinking in terms of left or right exposure bias, we should only talk about proper exposure of the important parts of an image. And that means talking about auto vs manual exposure, exposure modes, exposure compensation (bias) and HDR techniques. – Which is basically what you did in this article, so thanks for that. Just, please, let’s condemn the term “ETTR” to the dust bin of history as yet another half-true, often-wrong photography myth.
Indeed the vast majority of cameras when using their standard form of metering (Auto, Matrix etc) use an algorithm that looks at different regions of the frame and attempts to maximise exposure without losing highlights, and improving upon that by comparing to databases of 1000s of image examples to identify the likely key elements of the image. Hence in the case of a landscape picture with the sun near the horizon (sunrise/sunset) they will attempt to retain the solar highlight detail; whereas when the sun is high in the scene they may allow it to be blown out as it is unlikely to be the subject.
Similarly, Nikon presents both Spot metering and Highlight Weighted Spot Metering. The former will slightly overexpose the subject in the spot region when it reads more light than the rest of the scene; and where the subject is in the Spot region presents less light than the overall scene it will slightly underexpose that. Because of this sophistication not always giving the ideal results, the latter Highlight Weighted Spot Metering further protects highlights even more by centring the exposure for the subject in the Spot region.
It’s important to remember that the metering systems we have today represent the knowledge and technology gathered for over 50 years of auto-metering photography, before trying to overlay a new mantra like ETTR on top.
“In other words, ETTR is equal to perfect exposure and thus neither “to the right” nor “to the left””
No, it’s not equal to perfect exposure. It is, as its name suggests, “to the right”. The first two images in this article prove it by showing that, although the “recipe” was followed, the final image is over- or underexposed. The advantage of ETTR is that is saves the most amount of recoverable detail for later on when you open the file in LR o similar and adjust the exposure until it matches your taste. It’s a technique to give you the most leeway to do that, that’s all.
Just a note on this: any time you lower brightness on an image, it will increase the saturation as well. This can be especially true for midtones in an image which will get darkened, the colour will intensify. Human eyes see less saturation in the dark, not more, so it can easily look unnatural. There are different ways to keep this in balance and often a vibrance or saturation slight decrease can be all it needs, sometimes you need to target it more. In dodging and burning work on beauty shots, often you’ll duplicate the layer mask for the dodging and stick it on a -saturation adjustment, and the opposite for burning where the saturation can decrease (but often not as noticeably).
Very true. The association between luminosity and saturation is different for a camera sensor than for our eyes. It’s one reason why Milky Way or Aurora photos often appear far more vivid than we can see ourselves (and easily can look unnatural if you’re not careful).
Thanks for the comment, very interesting remark.
As always, a very helpful article. Thank you.
At the risk of sounding snide (which is not my intent), would it be possible to add red framed squares to the last three examples to indicate the metered spots? This would allow readers see which part of the image was used as the baseline.
I ask this because years ago I was reading a well-regarded book (Peterson? I have forgotten the name), and the author would show an image and write, “I used my spot meter to get the correct exposure.” The principle was clearly stated, however since the selected spot was everything in this method, the photo/text did not quite offer a completed example of application, because the author did not show the spot that was metered.
In particular, for the lovely sun star over the dessert, I assume that you did not measure the sun (that would be bad for the camera and your eyes), so did you use a part of the sky? If that is the case, how close or far away to the sun did place the spot meter box?
Thank you, Alex! I didn’t take your comment to be snide at all. I’ve updated the article with pictures of where I spot metered on those three final images (to the best of my recollection). You’re right that I didn’t measure the center of the sun for the third image, although I was right up against the edge of it because I did want to maintain details in the nearby region. I used live view, so there wasn’t any risk of damaging my eyes, and I took the photo fairly quickly to minimize any risk of damaging my camera.
Thank you very much for taking the time to do this. The metering spot for the sunburst was a bit closer than I imagined, which is why such information is helpful when trying to improve techniques.
Hi Spencer for this excellent article. One thing that always bug me in printing is to avoid having over-exposed regions on a print such as with the sun , or very bright clouds where I end up with a white spot where practically no ink is applied to the paper. How can I avoid this problem ? and how close to over-exposure can I print with enough density of inks to avoid serious fading in theses regions over time ?
regards
Hi Spencer, nice article as always. What do you think of using highlight metering instead of spotmetering and after that boosting the exposure to a certain amount?
sorry, I think the official term is: “Highlight-weighed metering”. Not all camera’s have this option.
Good question. I wish that Nikon would give more technical information about how highlight-weighted metering works, including how large a highlight needs to be in order to count, and where Nikon will place the highlight on the histogram (probably brighter than middle gray?). The technique you describe certainly might be possible, but I tend to doubt that you’d be able to get away with the same +EV setting for every photo.
Hi Cees and Spencer,
The role of the camera’s reflective light meter, in spot metering mode or centre-weighted metering mode, is to recommend an exposure such that a middle‑grey luminance in the scene will be rendered as a middle‑grey relative luminance in the reproduced image. E.g. an 18% grey card will render as a CIELAB lightness value L* circa 50; gamma‑encoded sRGB tuple (118, 118, 118).
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Luminance is a photometric measure, which is a measure of the perceived brightness to the human eye. Whereas, the camera’s sensor is a radiometric detector. Luminance is a perceptually weighted function of radiance. For sRGB primaries, the linear relative luminance Y of a linear sRGB tuple is given by:
Y = 0.2162R + 0.7152G + 0.0722B
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Taking log₂ of each coefficient gives its equivalent exposure value EV:
R −2.2 EV; G −0.5 EV; B −3.8 EV
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So, if we have a scene illuminated by only a blue spotlight and we are using an auto-exposure mode, the camera will, in effect, use an exposure compensation value of +3.8 EV; resulting in severely blown highlights, even in the raw data. Highlight-weighted metering mode is designed specifically for this and similar situations; it ignores small specular highlights in the scene, but larger highlights are metered.
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Further reading: Nikon NPS article Technical Solutions | D810 TIPS | Highlight-Weighted Metering
nps.nikonimaging.com/techn…highlight/
Pete, I really appreciate this info and link! I couldn’t find anything this specific about highlight-weighted metering when I was writing the article initially.
You’re more than welcome, Spencer. If you have any questions, by all means send me an email.
Best wishes,
Pete
Hello
Many thanks for sharing this very helpful knowledge. On Spot Metering though – do you think it works excellent in cool early morning temperatures, but as the temperature gradually rises and the rising heat waves start interfering and the accuracy of spot meter gets impacted …?
Another very informative and well-written article Spencer, thanks !
I was wondering whether the max +EV value that allows to recover highlights depends on the ISO setting you’re using?
Awesome! Thanks! I’d been using spot metering to meter off my highlights, but I hadn’t been pushing it to the right simply because I didn’t know how far to go and hadn’t gotten around to testing it. Now this gives some baseline, especially because I had a D750 so it’s likely +2 – +2.7 is the right ballpark for me based on your results. I’ll probably err on the safe side and just use +2 or +2.3 for a start and even give it a quick test next time I’m out with my lovely behemoth camera.
Dear Spencer,
Thank you for this very good article! I recently practised the technique you describe, picking it up from the guys from FastRawViewer. It works quite well.
Allow me to add 2 remarks:
– The spot metering should be on the brightest highlight THAT YOU WANT PROPERLY EXPOSED. There may be even brighter spots of which you don’t mind that they’re clipped. Maybe some readers might be misled without that specification.
– To be on the safe side, I apply exposure bracketing around the extra (eg +2.7 stops) exposure