Digital Photograpy in the dark.

September 2, 2007 7:14 PM

Low-light DIGITAL photography without the smears or grainy colored dots? Long question and possibly NSFW conversation inside.

I’m a totally amateur photographer thrust in to producing more than just the holiday snaps. I have 4 digital cameras ranging in quality from my 6 year old 3MP tiny-lensed model to a 12mp DSLR with a couple others in the middle. I have this problem with all of them, so I know its something I’m doing wrong. :-)

My well-lit or studio produced photos are spot on and I’m quite pleased with them.

Unfortunately, my low-light or nighttime photography is plagued by one of two things:

1) Thousands and thousands of multi-colored dots in all of the darker portions of the photo because of the lack of light

Or

2) smeary motion-lines caused by the slower shutter speed (needed to let in more light, see #1, rinse, repeat)

Sometimes, I would like to light the scene with, say, only one incandescent bulb, or moonlight, or candles or very low lighting, or low ambient light, so that I can capture the subtle shadows cast and have a general intimate, tense, dangerous or darker feel to the photoset. However, invariably, every setting or combination of settings I come up with produces one or both of the above situations, ruining the entire set. I have to resort to using a flash just to get a few shots that I can take a chance at salvaging by artificially adjusting the levels in Photoshop.

For the type of photography I produce, it’s not practical for the camera to be mounted on a tripod and the subject to remain perfectly motionless for every shot. Sometimes I need the subject to be able to move around and/or move into a pose and I want to catch that process.

The answers I can find either tell me I need more light, which ruins what I’m going for, or the tripod solution, which again, ruins what I’m going for.

Basically, what I see when I’m standing there is how I want the photos to come out.

So, what would the (ballpark) proper settings (ISO, shutter speed…) be for a photo session taken in low, ambient light, and with a digital camera?

What’s weird is that I never had this problem with old auto point-and-shoot 35mm film cameras with no settings. I could take beautiful photos by candlelight and the black parts were jet black and the darker hues were perfect. Unfortunately the nature of my photography now precludes me from using film (you know, candid photography, wink-wink-nudge-nudge-say-no more :-)

Thanks in advance, all!

XO

posted by sandra_s to media & arts (31 comments total)

I'm curious what lenses you're using. Doesn't sound like you even need a zoom, so a super-cheap 50mm might help your situation a bit, since you'll get more light in to the frame.

Super-low light, non-still photography is just a constant fight, if you ask me.

One option is to use some sort of soft lighting that will not really affect the shadows you want to cast - some studio lights, basically.
posted by tmcw at 7:40 PM on September 2, 2007

Low light digital photography is usually plagued with the problems that you mention. It's a nature of the way digital cameras work.

For a proper exposure, you end up using a very high ISO (like 1600 ISO or 3200 ISO), a very wide aperture (2.8 or wider, more like 1.8 or 1.4), and the slowest shutter speed you can. Even with that, your photograph ends up being severely underexposed.

1) Thousands and thousands of multi-colored dots in all of the darker portions of the photo because of the lack of light


This is most likely digital sensor noise. Noise should be better with your digital SLR than your point and shoot camera due to the nature of the SLR camera's sensor, specifically size and sensitivity of the sensor. I find that noise reduction software like Noise Ninja greatly decreases the "dots" and I use it on all of my shots that are low light.

Different cameras have different qualities of noise. It's hard to say how good or bad your SLR is with noise without knowing what make/model of SLR you have. The best noise performance I've seen comes from the Canon 5D body, BTW.

2) smeary motion-lines caused by the slower shutter speed (needed to let in more light, see #1, rinse, repeat)


This could be caused either by camera motion (you, the photographer moving slightly as the camera is taking the photo) or subject blur (your subject moving, slightly). For a fast moving object, I tend to use a shutter speed of 1/125 or faster. Your mileage may vary.

As for your personal camera-shake (no matter how still you think you're standing, you're probably moving the camera a little), the typical rule is to use a shutter speed of 1/(effective focal length) if you are hand holding the camera (AKA no tripod).

So if you're using a 50mm lens on a dSLR with a cropped sensor, then your shutter speed should be about 1/80 or faster. Of course, 1/80 or faster will often result in an underexposed photo, even at 1600 ISO and f/1.4.

I've found that to get good results with a slower shutter speed than recommended, you've got to a) learn to hold the camera very very still; b) bolster the camera and minimize shake with your foot/arm stance, say, with elbows tucked in, chest puffed out, feet at shoulder width; c) shoot in continous mode; and possibly d) use a chain-pod or other object to help stabilize the camera.
posted by kathryn at 7:42 PM on September 2, 2007 [1 favorite]

The problem you're running into is, to borrow a physics term, non-trivial.

The noise you're getting in the darker areas of the photo is sensor noise. It's the digital equivalent of film grain. You can minimize it by turning the "film speed" (ISO) down, but that will decrease sensitivity accordingly. Some digital camera sensors have lower noise than others (in general, but not always, the more you pay, the lower noise you get...low-noise circuits are not cheap to engineer). One of the major drawbacks of digital photography versus film is that with a film camera, you can always change to a less-grainy film (say, Tri-X to T-Max); if you have a noisy sensor, you're basically stuck with it unless you replace the camera.

So really all you can do is dial the ISO on the camera down, and then use longer shutter speeds to compensate ... and use some type of camera support to compensate for that. If a tripod is out, maybe a monopod will work. Alternately, you can consider motion-compensating lenses, if they're available for your SLR system (probably), but they'll only buy you a stop or two at most.

But there's no real magic-bullet solution that will let you shoot in low light at a high ISO with your current camera's sensor and not have any noise. (Although you can remove some noise in the dark areas by raising the black point in your Levels in post, but I'm assuming you're already doing that.) The craft of photography is essentially an exercise in balancing tradeoffs.
posted by Kadin2048 at 7:44 PM on September 2, 2007

Non-trivial is a very good description of the problem.

There are two main sources of noise. One is systematic -- some pixels are hotter than others. One is random -- at low light levels, some pixel get luckier than others.

If you're really interested in low light digital photography, there's a group who gets the problem -- astrophotographers.

Tricks they use. Cold is good -- cold means less noise. Dark frames -- put a lens cap on, take a photo. Anything that photo captures is noise, subtract that from any real image you take. Alas, one trick they use you can't -- take lots of photos and stack them. Stars don't move much, and when they do, you can stack them by realigning, since they only move in the focal plane. Real people at single-digit meter distance move in far more complex ways.

But really, you're fighting physics.
posted by eriko at 7:55 PM on September 2, 2007

Is this really a digital issue? It's not like light issues solve themselves because you switch to film. I think maybe more your memory is fuzzy on how good those old cameras were.

I mean, there's a reason why they invented f/1.2 lenses before digital existed.
posted by smackfu at 8:10 PM on September 2, 2007

Well, if the OP is getting blur from a slow shutter speed, bumping the ISO down is only going to make the picture even blurrier and for most applications motion blur is worse than high-ISO noise.

One possible suggestion is to shoot to the right. Let's say you're aiming for a low-key picture with rich shadows and to get that effect with the available light the meter says 1/100s, f/2.8, ISO800. You would actually get less noise if you were to shoot in RAW, expose at 1/50s, f/2.8, ISO800 (giving you a picture that's lighter than what you wanted), but then in your RAW conversion, dial the exposure down -1EV.

But if you're getting motion blur, my guess is that your shutter speed is at 1/50-1/10s already. So really, the only thing that can help you by that point is to get a lens with a brighter aperture.
posted by alidarbac at 8:14 PM on September 2, 2007

You need more light. If you set the light up correctly (shadows and such where you want them) it should be easier to correct for "too bright" than for blur or noise. It can be hard to get right (hint: flash is usually not the way to go) but you can see some examples in, e.g., Angel the television show, where they had still basically bright light but used the camera to create a darker feeling.
posted by anaelith at 8:17 PM on September 2, 2007

Neither of your problems are digital ones, they're the same -- or worse! -- in film, too.
1) Thousands and thousands of multi-colored dots in all of the darker portions of the photo because of the lack of light

This is noise -- in film, it's grain. Digital's actually getting better at this: 1600 ISO digital files can have considerably less noise than film, which is grainy as hell at 1600. You have two choices here: learn to love it -- and high grain can be a really great look, or move to a lower ISO setting.

2) smeary motion-lines caused by the slower shutter speed (needed to let in more light, see #1, rinse, repeat)
As kathryn says, this is just camera shake. Your shutter speed needs to be at least 1/[focal length of your lens], more if you've got a cropped sensor.

You need to get more light in that space of time. There are basically three things you can do:

1. Get a lens with an extremely fast aperture, like f/1.4 or f/1.2. These can cost quite a lot of money, but for low-light work they're great.

2. Use shorter lenses. If you have a 200mm lens on, you're going to have a hell of a job getting a shutter speed of 1/250th or greater in candlelight. But with a 40mm lens? Easy.

3. Bounce flash. Flash doesn't have to kill the mood of your shot, it just has to add enough light to it so that the camera can capture it quickly enough. If you get a flash that points upward, you can dial its output way down, bounce its light off the ceiling, and you'll get just enough light in to get the shot, but it won't show up on film. You know how you see movie sets and they have monstrous lights, but the eventual shot looks dim and moody? Same here.
posted by bonaldi at 8:25 PM on September 2, 2007

Ooh, and fourthly, you can drag the shutter.
posted by bonaldi at 8:26 PM on September 2, 2007

You didn't have that problem with film, right? BUt the film you wre probably using in low light was b/w film. So, convert your digital shots to b/w. They'll be grainy, as the "noise" is turned into "grain", but they'll look gritty then.

If you shoot RAW, you can apply a generic amount of "color noise reduction" in your RAW converter. If you're shooting jpeg, well, the jpeg algorithm seems to acentuate noise, to my eyes.

What bonaldi said, on #1, above, fer shure. Canon's 50mm f/1.8 is cheap as hell.
posted by notsnot at 8:49 PM on September 2, 2007

noise ninja works miracles. as does neat image. (I use neat image).
posted by devbrain at 9:01 PM on September 2, 2007

I wouldn't spend money on anything faster than a 1.8 for what you are doing. The depth of field is so narrow even at 50mm that a 1.4/1.2/1.0 is a speciality lense at best requiring massive amounts of practise. And they are expensive to boot.
posted by Mitheral at 9:23 PM on September 2, 2007

1. Use the SLR - it has the biggest sensor plate, this gives it a significant advantage.
2. Use a fast lens (eg F1.8), or your fastest lens if you don't have one, and open the aperture right out, while zoomed as far out as possible. (ie f-stop as low as possible)
3. Set the ISO to as high as you can before the noise starts to bother you. Don't let it auto-adjust it.
4. You can't use a tripod, so check out all the other methods people use when they need stability but can't use a tripod, eg, the string tripod, or adding mass/inertia to the camera like the "steadycams" that amateur video camera users make, or pushing the side of the camera into a nearby wall while taking the shot, etc etc
posted by -harlequin- at 9:53 PM on September 2, 2007

I need the subject to be able to move around and/or move into a pose and I want to catch that process

Ah, that's the critical part. You want the final image to be crisp image of Person in Position A, blurry movement into Position B, crisp Position B, yes? (somewhat like this or this)

It would help a lot to know what camera and lens you're using. That you're getting noise that bad strongly suggests it's a point-and-shoot instead of a DSLR. If so, you've probably got pathetically low limits on exposure length. A minute or (likely) less. But if you can get your hands on a camera that's got a bulb setting, long exposure and low ISO is the way to get this done. A long enough exposure will "freeze" anything that's mostly holding still and (depending on what proportion of the exposure time is spent moving from A to B) will either blur or render invisible the movement in between. The low ISO minimizes noise while stretching out the time (good) needed to get said shot.

This is EV3-ish territory, which most cameras meter poorly and leave autofocus hunting for something to lock on to. So turn on a bright light first and lock focus, then switch to candlelight and set everything else by EV chart. Even though it sounds counter-intuitive, stop down instead of opening up. Since you need lowest possible ISO and enough time to freeze two (or more) separate positions, you need lots of time. Opening up more is how you buy the time.

Don't worry about the subject not being perfectly still. In long exposure, "mostly still" is what counts. (insert Princess Bride joke here)

The Nocturnes is an excellent resource if you want to get into this more.
posted by nakedcodemonkey at 10:20 PM on September 2, 2007

Whoops, I meant "Stopping down is how you buy the time".
posted by nakedcodemonkey at 10:21 PM on September 2, 2007

P.S. You need a tripod. Motion (subject) blur requires time. Fast lens or no, any exposure long enough to capture the desireable motion blur is more than long enough to catch camera shake. Stabilize that camera.
posted by nakedcodemonkey at 10:29 PM on September 2, 2007

You *might* benefit from an image stablized lens which let's you take photos at slower shutter speeds without camera blur. It won't help with moving subjects though.
posted by Good Brain at 10:42 PM on September 2, 2007

I think the best advice in this thread is from harlequin, because some people seem to have not paid attention to the fact that you don't actually want blur.

Quoted for other answerers:
For the type of photography I produce, it’s not practical for the camera to be mounted on a tripod and the subject to remain perfectly motionless for every shot. Sometimes I need the subject to be able to move around and/or move into a pose and I want to catch that process.

The answers I can find either tell me I need more light, which ruins what I’m going for, or the tripod solution, which again, ruins what I’m going for.

You need a camera with a high-quality sensor. Your 12mp DSLR ought to be newer, so that really should be the one you're using. You may need a bigger/better lens.

Important: Go through your DSLR's manual, or do some googling, and find out what ISO ratings it does some artificial boosting for, and what ISO ratings it just lets the sensor handle itself. Generally ISO 3200 on a digital is boosted, i.e., it takes the picture and does some further processing on it to try and get more detail out of it. It necessarily amplifies the noise dots.

If it's a good DSLR, you should be able to do ISO 1600 without it getting too noisy. Use the smallest f-number you can manage, and try a variety of exposure lengths to see how it all looks. Don't be afraid to bump down the ISO from its max (e.g. if the max is 3200) to experiment, even though it's counterintuitive.

You are probably pretty frustrated with this; I've been there. If you feel like you're dumping too much money into this to make it work digitally, remember, you're saving a ton on film... though if you're at your wits end, maybe you could sell the DSLR and buy a bunch of film anyway.

Experiment!
posted by blacklite at 10:49 PM on September 2, 2007

Oh, also: you might be able to find a local place that will let you rent lenses before you go out and drop a bunch of money on them. Try a 1.8, see if that'll work out for you, if you don't have one already.
posted by blacklite at 10:51 PM on September 2, 2007

(Of course, what you really want is a 85mm F1.2, which will let you do anything (I hear it even buys you drinks and takes you out for nice dinners)... and so do I. But I am a long way from a professional and $2100 is an awful lot of money. Still, fantasizing is nice.)

(Okay done now. For real.)
posted by blacklite at 10:56 PM on September 2, 2007

how do things look if you actually make a print from one of your dslr photos, or view it on screen at intended viewing resolution? I ask, because there are a lot of flaws that are obvious when you are pixel peeping that aren't that noticable when the whole image is sized to fit the screen or printed at 8x10 or less.
posted by Good Brain at 11:05 PM on September 2, 2007

If you want to do long exposures at night, you'd be better off doing low ISO (like 100) for longer, to get less noise. You might also want to try dark noise subtraction.
For moving subjects, there's no replacement for light. Wider apertures are nice but they give you a shallow/narrow depth of field that make focusing somewhat challenging, particularly in low light. For really playing in the dark you need at least a flash and two or three is better (and diffusers and reflectors and whatnot). But even one good flash can give you alot more options.
posted by doctor_negative at 11:18 PM on September 2, 2007

The answers I can find either tell me I need more light, which ruins what I’m going for, or the tripod solution, which again, ruins what I’m going for.

And... they're right. Stanley Kubrick had a f/0.7 lens designed for him to film in candlelight.

That said, he was working in film, which is a whole different ballgame for a variety of reasons. You, on the other hand, are working in still images - and that means you can do a lot more with much cheaper lighting.

There are two 12mpx DSLRs I know of that you can actually buy - the Nikon D2X and the Canon 5D. The second is a stellar performer in the high-iso category, so I'm going to assume you're using the Nikon.

So here's yet another solution: shoot with off-camera flash, underexpose the flash and you should be able to get the look you're looking for. Look through any fashion magazine spread, find a shoot that looks 'underexposed' and i can pretty much guarantee you it was shot with enough wattseconds to blind you long enough to crash a car while driving.

Instead of getting better more expensive gear, throw that camera into manual mode and learn exposure! Underexpose for your flash. Underexpose in general. Expose normally then drop that exposure a stop or two in photoshop.

Oh, and ditch the P&S, they - as a rule - suck in anything but bright sunlight.
posted by jedrek at 11:24 PM on September 2, 2007

As stated above many times, there is no good solution for shooting in very-low-light situations. Even film has this problem to an extent, but digital is quite a bit worse.

The real solution is the same one people use when they have to shoot moving pictures with moody lighting: they fake it. That's not the answer you want to hear, I'm sure, but it's really the only way. If you've got some control over your scene lighting—and it sounds like you do—then you're going to have to increase the amount of light in the scene, period.

Plenty of movies have supposedly dark scenes, but go to a film set and more often than not they've got giant lamps blasting people with lights even if the scene is supposed to have low-key lighting. (In fact, the term "low key" is a specific lighting term that tells you how to place the main light in a scene.) But how do you increase the amount of light and still get that candlelit effect? Contrast! Put the light exactly where you need it (like on the subject's face) and absolutely nowhere else.

A really good example of how this works is any old black and white movie that has a scene with candles in it—the 1946 adaptation of Great Expectations comes to mind. There's a scene where Pip (or Estella?) is walking down a dark hallway with a candle lamp serving as the only light source.

To actually film that scene with just a candle would've produced completely unusable footage, so what they did is they took a very narrow spotlight and just aimed it at the section of wall where the candle was in the scene. As Pip walks down the hallway, the bright light follows the candle, and the rest of the scene is pitch black. Because it's an older movie and (I'm guessing) lighting technology wasn't as sophisticated, the spotlight effect is obvious to today's audiences (hence the reason why I say you should look at old movies—you can see the seams), but I'm sure it looked exactly right in 1946.

Utilize similar techniques when setting up the lights for your still scenes and you'll have a lot more success fighting grain and noise. Until we get those magical cameras that work just as well as the eye in low-light settings, this is the best option.
posted by chrominance at 1:04 AM on September 3, 2007 [1 favorite]

Why not shoot with the lights on (if you have control of that) and then just adjust the photos in Photoshop? This also gives you the opportunity to give the subjects a bit of a touch up and hide those blemishes, adjust their skin tone etc.
posted by lemonfridge at 2:40 AM on September 3, 2007

Unfortunately the nature of my photography now precludes me from using film (you know, candid photography, wink-wink-nudge-nudge-say-no more :-)

You could develop it yourself.
posted by Brandon Blatcher at 6:12 AM on September 3, 2007

I'm going to second the "use movie lighting techniques" and fix it in photoshop (or whatever) after the fact. Yes, it's more work/time but it's far easier to go dark from a correctly exposed image than to rescue a crappy digital shot. Check out Strobist too.
posted by jdfan at 7:24 AM on September 3, 2007

I don't think the speckled problem is unique to electronic sensors. When we used film, the dots weren't as colorful and we just called it "grain", right? It's the color that bothers us and strikes us as a new problem.

Now, those colored dots are uglier than grain is. I don't have a good idea about how to avoid/remove it.

Maybe once we have layers of sensors instead of columns of sensors, that problem will go away.
posted by cmiller at 9:19 AM on September 3, 2007

One way I reduce camera shake and blur in low light situations is by using a short self-timer, so I'm not pressing on the camera while the shutter is being tripped. It's a fix specific to that type of motion blur, of course, but it's been helpful.
posted by Dean King at 9:43 AM on September 3, 2007

Supposedly fuji makes the best small cameras that work well in low light.
posted by delmoi at 12:17 PM on September 3, 2007

Fuji makes the best small cameras that work well in low light, but not all small fuji cameras work particularly well in low light. The f10, f30 & f31fd all have much larger sensors than your average compact point and shoot and have quite good low light performance as a result. DSLRs will generally be lot better though.
posted by Good Brain at 11:34 PM on September 3, 2007