Let’s talk about noise. Not the lovely Swedish lullaby my friend hums at me down the phone but digital noise in our photographic images. Most of us profess a serious allergy to it such that noise control has become a major USP for many camera models. One of the many features prospective buyers look for is noise control at higher ISOs. Models like the Nikon D4S and Sony A7s market themselves specifically as clean imaging devices, having listened to (preyed on?) the market’s feverish insecurities about the dreaded grain.
There I was about to share actual photos on a mirrorless forum during my breakfast coffee when I stumbled upon a posting there about how the latest Olympus model has ever so slightly less RAW noise grain at ISO 6400 than previous models and what kind of mystical magic must be at play (yes, point and laugh all you A7s owners with your shameless ISO 409,000!). The fact that I couldn’t see any real difference in their comparison myself (and my eyes are reasonably good) only emboldened my disdain for the obsession over such minutiae. Would their purchasing decision really be determined by the perception of slightly fewer chroma particles at 100% magnification?
I won’t go into the science of noise and signal amplification as Nasim has covered that in the past with far greater expertise than I could ever hope to. This is more of an introspective article, considering whether or not noise is truly the nemesis we’re seemingly programmed to think it is. Certainly the endless fawning over super-clean but mediocre images undertaken by some online reviewers feeds this antipathy.
Let’s be clear; one of the primary advantages of digital photography is noise control. With film (I was going to write ‘back in the days of…’ but of course many of you happily still use film) one has to change the film according to the situation, and higher speeds mean more grain. Keeping the film speed lower means a careful selection of subject, technique, lighting and timing. But with digital we all have the freedom to flick the dial and shoot in near darkness while getting a usable image, which we can probably later smooth with noise reduction software. It has enabled shooting possibilities that perhaps weren’t available in the pre-digital era, especially shooting action and sports. Bravo digital.
But have we become so conditioned to believe that we must be averse to noise at all costs? Even to an irrational extent as on that forum? Yes, noise is intrusive and unpleasant and if we raise the ISO high enough we get more of a watercolour painting smeared with hummus than an actual photograph. More noise also limits our printing options, peppering the print with a pox of pernicious pixelated pimples. No one wants that.
What about the creative inclusion or acceptance of noise as part of the artistic expression or merit of the image? Can it not render a certain authenticity or nostalgic look, especially in black and white? And if so, should we be so averse to it? Yes, when it overwhelms the image itself and obscures the subject. Some may argue that if we want a certain look it is better to start with a clean image and add noise to it with software. I can certainly accept that. Not sure if the result is as authentic but it’s doable.
What if we don’t own a D4s or equivalent beast? Isn’t a little noise worth getting the shot than not? If the only way to use a favourable shutter speed in the available light is to use a higher ISO, then let’s go for it. A dusting of noise is better than no image at all.
Like my mother used to tell me when I refused my oats, a little grain never hurt anyone. Have we become so sensitive to the sensor’s sensitivity that we’ll ignore the image itself? There is an abundance of images from decades ago that rate iconic status but are riddled with noise. I doubt the people viewing them complained about it instead of stepping back to enjoy the picture. OK, perhaps they didn’t know any better, and, yes, perhaps if those images were taken with digital now they’d be cleaner and easier to tidy up with software. But perhaps they would have lost something other than just the noise too.
How much noise one tolerates or finds acceptable is a matter of individual preference. It certainly matters less to me than the people who apparently have time to waste chastising me for having it in my images. I’ve used a full frame sensor in the past and enjoyed having useable images at very high ISOs. But I use a smaller sensor now and happily shoot up to ISO 6400 if I need to. More often than not I rather like the bristly texture; perhaps it reminds me of my stubble; who knows? But it is not much of an issue for me these days. I use fast lenses and I don’t often shoot in the dark unless I’m shooting long exposures, in which case I’m using the lowest ISO setting anyway. And I don’t feel the pressing need to simply own a device that could shoot in near darkness. So, for my particular needs I have what works for me. Beyond this sufficiency and the portability of my chosen system the artistic value (if there is any) of my images is far more important to me than having the biggest, cleanest, most expensive tool to make it. Your preferences may be different, of course.
I won’t pretend I don’t clean some of my high ISO images with noise reduction software. Of course I do (although I have deliberately not cleaned any of the images in this post). And I always shoot RAW which renders the noise as a much finer grain that cleans more smoothly while leaving more detail intact. But my attitude to noise is far more indifferent these days. The more I shoot, the less I care, and while I consciously try to keep the noise to a minimum where possible, I’m far more obsessed with making the shot I want than the speckles of noise pollution that come with it.
Well, sorry to prattle on. It’s late and I’ve run out of vanilla biscotti coffee, so time for a Swedish lullaby, I think. Where did I put my phone?
Thanks for the eye-opening article on digital noise! When I process b&w pictures I often add grain in the Nik Silver Efex or similar tool to make especially background areas less sterile. Now I will try my D7000 with deliberately higher ISO to see if it gives me sort of filmy grain more naturally in the picture.
Maybe a bit late in commenting, saw this good article just!
Noise/grain – old school using Tri-X doing large (My faster used his Leica to do up to 3 – 4 feet wide for interior decoration, to be viewed at some distance) or pushing to 6 400 ASA accepted noise/grain.
Reason is perhaps the noise kicks in using available light, we accept(ed) a more dirty look when shooting in low light, just like we accepted a big enlargement will have not knife sharp edges/details.
Getting it too perfect (aka pixelpeeperapproved;-) tends to kill the feeling of the situation, thus I’m not yet fully sold on my Fuji compared to an old Leica lens..
-J!
Not wishing to go against the grain here (pun?) regarding the acceptability of noise and settling for it by calling it “grain”. Yes, Ansel, et al, did produce photos with plenty of noticeable grain. Why? As most likely, that is only what they had to work with during their days. Did they oooh and aaah over the softness and grain? That’s doubtful, unless they were going for an effect. I’ll betcha if Ansel were alive today, he’d be shooting a lot of digital back medium or large format photos, all the while cooing and chimping at how clean and noise free his RAW files are.
Settling for noise — besides that used for artistic and interpretive purposes — is kind of like wearing pitted glasses because it’s so cool looking through them. Fine. Wear pitted glasses. Me, I’d rather wear optically clear glasses, spattering them for effect if I want it, BUT, I have control over that and do not have to settle for the “look”.
Some take umbrage to software manipulation of their files. Cool! You probably only shoot JPGs too ‘cuz your files come out perfect. That’s wonderful, but with software, one can take files to the next level and beyond. Hey, one can even add noise (grain) to a clean file if they wish!
I’m not trying to create a flame war here. What I’m trying to discern is why noise is so valued in this thread. Seriously: chroma, let alone luminance? From the responses to the post, it sounds like most are trying to give credence to something that is inevitable, even with today’s tech. Tomorrow will be another story. Yes, we settle for noise because that is all we can do at the moment.
“From the responses to the post, it sounds like most are trying to give credence to something that is inevitable, even with today’s tech. Tomorrow will be another story. Yes, we settle for noise because that is all we can do at the moment.”
Photon shot noise determines what is, and what is not, achievable. Future technology will improve the quantum efficiency of sensors, but by how much? Suppose that the best current sensors are 50% efficient. The signal-to-noise ratio (SNR) is given by the square root of the number of photons counted. Therefore a 100% efficient sensor would reduce the image noise by only half an f-stop (29%); or for the same image noise, it would increase the light sensitivity by only one f-stop.
Noise is here to stay, irrespective of future technology. There are some highly-complex noise reduction algorithms, but they can’t recover signals that haven’t been recorded! E.g. if the deep shadow areas have only one photon hitting the pixels then a one f-stop lower exposure will mean zero photons hitting the pixels — the noise will be zero, but the signal will also be zero. E.g. we have 64 photons counted by a pixel while the shutter is open. The SNR will be 8 (very poor). Successively reducing the exposure in increments of one f-stop yields photon counts of: 32; 16; 8; 4; 2; 1; 0; 0; 0.
If we double the area of each pixel — which means halving the number of megapixels on the sensor — we double the number of photons counted; therefore we improve the light sensitivity by one f-stop. However, camera buyers are demanding more, not fewer, megapixels *and* increased light sensitivity. The demand for very sensitive cameras having, say, 4 to 8 MP has become far too small to be worth manufacturing them. Very high quality 6×4 and 7×5 inch prints can be produced from 2 MP images; and 2 MP HDTV screens (1920×1080 pixels) can render stunning images.
Andrew, I am likewise not trying to start a flame war. I didn’t get the impression that noise/grain is being intrinsically valued in this thread. Far too much fuss is made about noise and grain; and many people have become so obsessed with it that their only enjoyment is in looking for it, criticising it, and trying to eliminate it — they are unable to enjoy the subject matter captured in the photographs.
The performance of modern high-end digital cameras is awesome therefore I struggle to comprehend why so many users complain about chroma and luminance noise. What on earth are these users trying to do with their cameras? I’m tempted to think that they know next to nothing about the art and craft of photography. Training courses might be able to improve their photography; better equipment will not.
Oops: “If we double the area of each pixel — which means halving the number of megapixels on the sensor —” No, it means dividing the number of megapixels by 4, duh!
Pete, maybe it’s the way I followed this post, but it sure seems to me what is implied is that noise is here to stay and we should live with it and not do a thing about it and call it artistic license. I absolutely agree that nothing can be done to eliminate noise completely with current technologies, but I do believe it will get better and better as time passes. Until then, we must live with it. On the other hand from reading the posts, it seems to be a consensus that doing nothing about it is preferable to minimizing it as best as one can achieve in camera and via software. If the tweaks don’t work, then that’s all one can do, so revert to the original, and consequently live with it. Sometimes we need to go beyond the boundaries in order to capture the scene by bumping up the ISO and/or making very long exposures which will create noise; understood.
BTW: the physics info you’ve offered on light and noise is much deeper and complicated that I ever imagined. No wonder camera companies have been taking so long to be where we are today in terms of noise reduction. Probably the best way to circumvent noise is to create an array of fewer but super giant pixels, therefor severely defeating noise. In order to accommodate these pixels, one would need at least an 8×10 inch sensor panel (or whatever)!
Andrew, Many thanks for your thoughtful reply. Discussing technical issues is, I think, very important; as is offering reasoned challenges to opinions.
Firstly, ignore my “Oops …” reply to myself, I think my original wording was correct. If it wasn’t then I hope someone else will correct it.
One thing that always bothers me is the promotion of false hopes for our future. I suppose manufacturers have a duty to promote false hopes. E.g. “Our new washing powder is much better at removing stains.”, which is advertising that has been endlessly repeated over the decades. Despite the numerous iterations of these ‘large improvements’, none of the products have actually improved by a large amount over the decades on a practical level. We still need to buy separate stain removers for stubborn stains. There is always a trade-off caused by the laws of physics and chemistry: a very strong bleach would remove most stains, but it would also bleach out colours and damage the materials used in our clothing etc. Making clothes out of stainless steel would provide neither warmth nor comfort; making them out of polytetrafluoroethylene (PTFE, aka Teflon by DuPont) also has its limitations.
With expensive items, such as camera equipment, false hopes and dreams can easily lead a purchaser down the pathway to financial ruination, which is very sad. I try hard to explain the fundamental laws of optical physics, not to promote myself (I write anonymously), but in the sincere hope that something I’ve written will save at least one reader of this website from financial hardship, or in some way help to improve their photography, preferably both.
Areas of technology that are in their infancy improve rapidly with the passage of time. Established technology such as terrestrial and satellite radio & television receivers has reached 95% of the limits imposed by the laws of physics — further improvements to the receiver signal-to-noise ratio cannot possibly yield noticeably better performance. Digital camera equipment is approaching the limits of the laws of physics; hoping for ever continuing f-stops of improvements is just false hopes and dreams.
You mentioned having an 8×10 inch sensor panel to accommodate super giant pixels. Yes, each pixel would be very much more sensitive to light. But, a camera lens *projects* its image of the scene onto the sensor. If you’ve ever used any kind of display projector then you will have observed that moving the projector away from the screen makes the image bigger and it also reduces its brightness: because the light power (the number of photons per second) is being spread over the increased area, therefore each square mm/cm/inch/foot of the screen is receiving fewer photons per second.
[WARNING: The following may start a flame war!]
When we carefully examine the effect of sensor size on image quality we find that, in theory and increasingly in practice, it makes absolutely no difference to their light gathering ability or to their signal-to-noise ratio, when each sensor has a similar number of megapixels. However, in my opinion, nothing can match the light gathering ability of a f/1 lens used on good quality FX cameras. A Micro Four Thirds camera (a crop factor of 2) would require a f/0.5 lens to compete. The equivalent lens on an 8×10 inch sensor would be either hideously expensive or simply impossible to manufacture.
When the available light is good in terms of both quality and brightness, and fast shutter speeds are not required to freeze movement in the scene or the camera, then 8×10 film will make even the best 36-50 MP FX cameras look totally pathetic in comparison. And never forget that cumbersome view cameras can achieve things that are impossible with fixed lens mount cameras.
When the available light is very low, and there is movement in the scene, then an FX format camera with a really fast lens does, and probably always will, outperform any other camera format. Not necessarily due to the laws of physics, more likely due to the law of supply and demand.
For general purpose photography, a high-quality modern pocket camera in the hands of an expert will, on average, considerably outperform/outshine non-experts using state-of-the-art camera systems.
I hope that was in some way useful; it wasn’t intended to be confrontational.
Pete
Good stuff Pete, that is very informative and revealing. And no, you’re not being confrontational; only knowledgeable.
Thanks for another great post. Years ago while attending a workshop by John Paul Caponigro he showed the attendees a number of original prints he had acquired by master photographers, a real treat to see some iconic images printed by the artists themselves. He even showed us several original prints by Ansel Adams. After gawking at some incredible compositions he asked us to look at the degree of sharpness and grain of the prints. And we were all astounded to then see in those prints softness and grain far exceeding what modern cameras and printers are capable of! But the images we were looking at never suffered from what we would today say was soft or grainy images. JP’s point was to put grain, sharpness into perspective and not let those subtleties drive your artistic expression. If you nail the story (e.g. compostion, exposure and subject) the sharpness and grain become minor players in the success of your photo.
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Thank you Ned. You articulated the point of the article perfectly :)
I used to own a D7100. Then I went to a D90 and a couple of weeks ago I got a D200. And you know what? I don’t regret it. Not. A. Single. Penny. Yes, I do own a D600 but I use it far less often than back when I got it. I’m just in love with the D200 and its autofocus system.
Over the decades, my clients have been delighted with my pictures, which were captured on suitably chosen films for my manual focus cameras.
If you continue making your retrograde steps for long enough, you might eventually learn how to become a photographer rather than a gearhead.
I am happy for you if a retro D200 is now your cup of tea……………, but it shock me reading you comparing a D200 AF to a D7100 ………………… I had a D100 (expensive) with its 6 megapixels sensor and it was far from beeing an excellent AF as the D7100… or D7200 (better) or D750.
To me with the quality Nikon D-slrs have reached there is not much interest to upgrade cameras anymore specially if you are not a wildlife or bird shooter. If your work is not to your taste or to the expectations of your clients get more training not more gear.
I really appreciate this article. It made clear for me a few things that I’d gotten away from- it’s far more important to have a strong, in-focus composition than fretting over noise in the image. Of course, as it relates to exposing “properly,” I always like to have less noise than more, but I won’t stress over it.
Thank you.
Exactly right Doug. Thank you :)
Best picture ever of a cat and I don’t even like cats but sure like that one, you rocked it.
Thanks Michael! That’s my friend’s cat. I’ll pass on the compliment :)
You noise looks great !
Thank you Jorge :)
Thank you for publishing this. I couldn’t agree with you more. We in photography tend to get so wrapped up in the minutia of technical perfection that we sometimes forget about the all-important artistic qualities of what we do: form, meaning, and emotion. My wife who works in watercolor and oils would laugh at the notion that a little “grain” could spoil a beautiful picture.
Thank you Warren :)
Excellent post, Sharif (as always) — and full of truth. Grain/noise has so much character. It certainly doesn’t work for every shot, but some of my all-time favorite photos are quite grainy by modern standards — Fan Ho’s street photography, for example — but the photos are wonderful regardless.
Great photos, too.
Thank you Spencer :)