Low light photo tips

September 2, 2008 7:52 PM

Low light photography workflow tips anyone?

First of all, thanks everyone for your advice here. I managed to find a reputable local camera shop and after fishing around for a few months on their used items, I bought a virtually unused (the warranty card was still in the box along with the bubble wrap) Rebel XT and a new starter 50mm f/1.8 to tool around with -- all for under $350.

Now as a photonoob, I need some advice about how you think through low light photography. I'm shooting handheld and without flash. Mostly (but not all) head-and-shoulders candids and food photos. Here's how I work through my shots and post-process them...

1) Open up the aperture as wide as I think the subject will allow in terms of depth of field.

2) Adjust ISO for light (generally these situations warrant 800-1600 the camera limits).

3) I shoot in aperture priority, with burst on, and AEB (2/3 stops on both sides) just in case the shutter speed and movement limits the exposure.

4) I shoot in RAW, and after I pick the best shots, I post-process in Aperture with a round of white balance and noise reduction (Noise Ninja), correct color levels, adjust saturation and pickup shadows/highlights (usually with the black point and recovery tools).

5) Finally I carefully edge sharpen paying attention to the noise level given the high-ISO I'm shooting in.

Here's a few examples.

I'm open to Photoshop which I use from time to time, but it's a bit time consuming for large batches.

Anyway, as a relative noob, is there something I'm missing in the technical details? Any criticism or tips on better low light shots (short of buying a D700) would be appreciated.

posted by drpynchon to sports, hobbies, & recreation (23 comments total)

Oh and be gentle -- I've only been at this for a few days.
posted by drpynchon at 7:52 PM on September 2, 2008

In low light I would shoot in time-priority because experience tells me that there is a maximum exposure time before shaking is a problem. Getting some kind of support can be super helpful, even if it's just a monopod or something. You can get much longer acceptable exposure times, which gives you a much larger usable aperture range.

I've never done much digital work so I don't have any comments on your software requirements, sorry.
posted by RustyBrooks at 8:02 PM on September 2, 2008

You've pretty much got it. The only thing I would change would be to ditch the exposure bracketing; just check your histogram after shots to check your exposure. If you're dinking around with bracketing you will miss out on your "decisive moments." The rule of thumb for printable sharp pictures is to keep your shutter speed above your effective focal length, in your case you want to be above 1/90sec.

And your pictures look great so far.
posted by volition at 8:11 PM on September 2, 2008

I'd second the opinion that you've got a darn fine handle on the problem. If there's one thing you can do, it's (when circumstances permit) try to cheat and boost the light level on your subjects, by strategically placing a white reflector (I've even used menus in restaurants). Every lumen helps with what you're trying to accomplish.
posted by pjern at 8:22 PM on September 2, 2008

You've got a good handle on it already, which is amazing if this is the first week you've had your camera. I'd add the following thoughts per point:

1. Just keep it open all the way in low light. ISO and shutter will be the limiting factors on quality (noise/blur), not DoF. Don't even worry about it.
2. Try and get it as insensitive as possible while still giving you blur-free photos. ISO 1600 looks fine when resized for the web, but a 8x10' glamour shot will need a less-noisy ISO. That's just an ideal, and it might not be practical if your shutter speed gets too low. The general rule of thumb is a shutter speed equal to (1/focal length) to minimize camera shake -- but you're on a crop sensor so double that value for good effect -- 1/100th second is your minimum shutter speed for that lens. Just make sure when you focus/meter, you're getting that value or faster. If you're metering around 1/500th, you have the leeway to change the ISO.
3. Burst is good. AEB is questionable, but it might be nice if you can take your time with a willing subject who's willing to hold a pose. But like volition said, though, don't let it get in the way of a candid. Shoot like crazy. Recompose. Shoot more.
4. Go easy. Bringing out the shadows will just add color noise. Don't WB everything. Your two example candids are fantastic without much WB. Atmospherics are part of the charm.
5. Sure. Again, just go easy.

One of my favorite PS techniques: Duplicate image layer. Set blending mode to soft light, Gaussian blur of 20-30px to layer. Opacity to taste. Softens blemishes and noise for portraits.
posted by cowbellemoo at 8:41 PM on September 2, 2008 [2 favorites has favorites]

Not sure the Rebel XT has a time priority mode. I'll look into it.

Also, I know about the rule of thumb re 1/effective focal length for shutter speed but, it seems like that's a bit conservative. For example, the two portraits I put up could definitely stand to be crisper but even at 1/13 sec they seem passable, especially for non-print work (the web). Is that rule of thumb a truism or myth in people's experience?
posted by drpynchon at 8:41 PM on September 2, 2008

it seems like that's a bit conservative. For example, the two portraits I put up could definitely stand to be crisper but even at 1/13 sec they seem passable, especially for non-print work (the web). Is that rule of thumb a truism or myth in people's experience?

That's luck. Luck is good. I've gotten sharp handheld 1s exposures by accident, too. Resizing for lower resolutions, burst mode, and a very steady hand will let you get away with snapping at slower shutter speeds, but I guarantee you that some potentially awesome candid shots will be a blurry streak and you'll kick yourself. I've been there. Gorgeous girl making some imperceptible gesture between moments and I'm so confident I have a fantastic shot but what I really have is blurry crap that makes me look like the greenest of wannabes.

Also: make sure the eyes are in focus. Blurry, indistinct eyes can ruin an otherwise sharp shot.
posted by cowbellemoo at 8:57 PM on September 2, 2008

The 1/EFL rule has a lot of leeway, and varies based on how steady the shooter is and the particulars of the camera and lens--I think the rule was geared towards getting an "acceptably" sharp 4x6 print using an SLR. The larger you print, the sharper you need to be, web images are very low resolution in relation to other uses of an image.

The real rule is: whatever gets a good shot for you is what you need to do. I tend to print big (10"x15" to 20"x30") and am pretty twitchy, so I keep my shutter speeds high.

Also, time priority==shutter priority==Tv on your camera dial.
posted by volition at 9:05 PM on September 2, 2008

Oh, here's one: You'll shake the camera just pushing the button, so continuous mode or timer modes work well. I often will do mirror lock + timer (canon drops the timer down to 2s when mirror lockup is enabled) when shooting at night.
posted by aubilenon at 9:08 PM on September 2, 2008

Always keep in mind that you're pushing your camera to its limits, so something's gotta give. The sensor can't be set to higher than 1600 ISO, the lens can't open past f/1.8, so the only thing you can vary is shutter speed.

Not really sure you need the exposure bracketing when you problem seems to be "there's not a lot of light in this environment" -- you're already underexposing most of the time, right? You could probably just take a series of measured shots in manual instead. Set the dial to M. Open up to f/1.8, set the ISO to 1600, start with 1 / [effective focal length]. Then take a few shots, look at the exposure. If it's still too underexposed, take a few with a shutter speed half as fast. Lather, rinse, repeat, until you start to intuit what settings work in what environments. BTW, On Canon dSLR's the "time priority" mode is shutter priority, i.e., "use the shutter I set and change the aperture accordingly while keeping the ISO steady." This is marked as Tv on Canon dSLR dials.

The 1 / [effective focal length] is just a starting point: it's a general guideline for making sure the majority of your handheld shots aren't ruined by photographer motion. Everybody's hands and arms are different. I would definitely go much faster than that if I were on a rocking boat or unstable surface, for instance.

The other factor is subject motion, which cowbellemoo mentions. Some people like a little bit of blur because they feel it makes the shot feel "artier" but a lot of the time it's distracting, and gives the impression (incorrect or not) the photographer failed at freezing action (even if that wasn't what they were going for).

Sharpness is relative to viewing distance and image size. Things that look alright sized down to at arm's length can look quite soft if you press your nose up to the image, especially if you know where to look. BTW, I agree with cowbellemoo. Having someone's eyes be in focus is a great tip.

If you are at 1600 ISO, f/1.8, and 1/13, I would suggest looking into
- a string-pod or monopod or tripod or other stabilizing device (heck, use the strap to stabilize)
- a remote trigger
- borrowing or renter wider and faster lenses (like a 30mm f/1.4 from Sigma)
- eventually upgrading to a camera with decent 3200 or higher ISO
posted by kathryn at 9:25 PM on September 2, 2008

Oh yeah, mirror lock is a great thing, even better, if you have a RF or even IF remote, so you don't get any vibration from the mirror going up OR from pressing the button.
posted by RustyBrooks at 9:47 PM on September 2, 2008

Re: mirror lockup...

Don't I lose the viewfinder with it? And if so, doesn't that add an extra 2 second delay wherein my subject will more likely drop out of focus in a candid?
posted by drpynchon at 9:53 PM on September 2, 2008

Like everyone else says you're already on the money for most of the low-light techniques. The only other thing I find useful is breathing technique; though that's actually something that applies to all photography in general. I normally inhale in two sharp bursts and then exhale slowly as I squeeze the shutter release; though I've heard of different people using different methods too. Works for me, YMMV.
posted by nihraguk at 10:02 PM on September 2, 2008 [1 favorite has favorites]

You'll probably end up bashing your head against a wall if you fight this too much. Free yourself from thinking that every part of the frame needs to be properly exposed.

I've hand-held my 5D at 800 iso at a 20th or a 15th of a second and had it printed in newspapers. Keep in mind that in low light, you'll have to be even pickier about what pictures you can take. If you're dedicated to working without a flash (and you should be, at least for while) realize that some pictures just can't be taken in low light. There's always a picture to be made, but it might be made using the subject to cover up the single light bulb behind them so you can have a silhouette. Or you might need to wait until your subject is near the single dim bulb. Don't let your histogram dictate your pictures, either. It's perfectly acceptable to have full black over large parts of the picture. It often makes for really nice moody pictures. Here's a portrait I took, for instance, where the room was pretty much dark; there were two windows with closed blinds on an overcast day. Expose for the highlights on the face, forget about the shadows, and you've got a picture that looks a little different and has some mood to it. This particular picture, I think, was with a d2h, so there's no way that I was shooting anywhere over 400 iso with it. Embrace your limitations.
posted by msbrauer at 11:53 PM on September 2, 2008

I agree with most of what you're doing. Stabilizing the camera only helps so much when you have a moving subject. I love shooting hand-held in limited light situations, you can get some really pleasing shots (and plenty of garbage shots that get thrown out).

The only thing I do differently from you is take advantage of the camera's automatic ISO feature. I usually use auto ISO with a maximum shutter speed of 1/30, along with aperture priority as you are already doing. This way, if the exposure requires longer than 1/30s shutter, the ISO will automatically be increased until it can get a shot with a faster shutter (or you reach the max ISO setting for your camera). Kind of nice when you step into a room with more light, to not forget that your ISO is higher than necessary and end up with noisier images as a result.

I think the two portraits you shared are perfectly fine, technically speaking. Like nihraguk says, pay attention to your breathing as you shoot, it helps. I think you've got a good handle on this. Some day, you might want to experiment with a budget flash diffuser and see what you can do with your camera's built-in flash. It'll help when you absolutely need to supply more light to get the shot.
posted by knave at 11:58 PM on September 2, 2008

Try a couple shoots with a tripod. I know they are big, scary, and slow at first, but be patient and you will start to make better pictures. You will be able to shoot at a lower ISO speed and choose whatever aperture you want (as long as you can get your subjects to be still). In the process of adjusting your tripod, you will begin to pay more attention to composition. You will also open the doors to countless experimental methods that simply aren't possible handheld.

Don't be deterred by the price or size of professional models. A $25 tripod from Wal-Mart will go a long way with a lightweight digital camera such as yours. In low light, a Rebel XT and cheap tripod kick a handheld D700's ass at image quality.

One more thing: aim for image quality in prints, not just on the web. If you get serious and want to make a bunch of prints, it will suck to realize that your great-looking 700px images with unsharp mask aren't good for anything larger than 4x6's.
posted by scose at 12:12 AM on September 3, 2008

You've got the right sort of lens for low-light photography. If you made no changes to what you're doing, I think you'd do just fine. I started out with a 35mm/f2.0 and it was excellent for this sort of thing. A lot of my early night photos are just point and shoot in automatic mode and they came out great. My top two issues were motion blur (camera shake) and sensor noise (ISO 1600).


Motion blur:

Nowadays, I typically use IS/VR both day and night to mitigate my hands trembling, and this has helped my night photos a lot. It compensates for the lack of a tripod. Now I can take a picture of christmas tree lights without it becoming an angry swarm of colored blobs. You said Canon, so if your body has IS, it should be free for you to enable it for all lenses and improve your photos globally. There are probably drawbacks (some IS/VR is incompatible with tripods) but I haven't encountered any personally with my Nikon.

If you have the patience for it, mirror lock-up could improve the sharpness of your pictures; you'll probably have to press the button twice for each picture. I could see this interfering with taking "action" shots, but it does seem to help the final crispness of the pictures I get from the camera when I'm doing tripod shooting. I've never tried mirror lock-up without a tripod, but presumably it works handheld just as well - and maybe more so, since a human is in theory less able to absorb mirror thwack momentum without moving at all.

When I first started shooting a friend set my camera into continous shooting mode, so I could just hold down the shutter and it would take several pictures. Looking back through the archives, I always took 3 pictures at a time - even though the camera could do more. That was my magic number, and usually I could pick one of the 3 to get something free of jitter and blur and correctly exposed and so forth. As I've improved, that's dropped to average around 1.1 pictures per shot, thanks in large part to IS/VR removing hand trembling from the equation. This opens the door to bracketing.

If you're comfortable taking 3 pictures every time you press the button, you could put the camera into continuous mode and then set it up for a (-1,0,+1) bracketed set and take those 3 pictures for every photo. You'll run into situations where you slip and miss one shot in the bracket and then all the brackets thereafter are offset by one from the prior brackets. I do a lot of landscape photography, so I just take the camera in and out of bracketing mode when I feel like it - it only takes a second or two each time. Initially I used bracketing a great deal but I don't use it much for single captures anymore. (Lots of HDR, though.)


Sensor noise:

The clearest thing I can say about noise is not to panic. Go look at a gallery book of black and white photos and check out how many of them have visible noise. Digital noise looks different, but it's just noise. You could continue to ignore it if it doesn't detract from the picture. If you do want to remove noise, there are a bazillion tutorials and many programs that can do so. Some have specific recorded profiles for individual cameras so that they can do it more precisely. I used a lot of Noise Ninja when I was dealing with high noise images in the past. I also posted a lot of images with noise intact. It's completely up to you.

If you're planning to print pictures, you should select a high noise picture and go have it printed and see what results you get. The way it looks on the monitor is only loosely related to how it will look when printed. It's important to have a sense of how much noise you are personally okay with having in a picture both on screen and in print, as then you can make effective decisions about whether to spend time removing it.


* Continuous == Burst. IS/VR == Canon/Nikon "SteadyCam". Bracketing == AEB.
posted by crysflame at 6:57 AM on September 3, 2008

As has been pointed out, these look great so far. If you really get into this, you might get an even faster lens, like the sigma 30mm f1.4, which is ~2/3 faster. Not a huge amount, but every little bit helps in this kind of thing. Anything faster than the sigma will probably cost a ton and really have issues with dof (not that the sigma might not already).
posted by pwicks at 8:34 AM on September 3, 2008

BTW, the Canon Rebel XT doesn't have auto-ISO. Auto-ISO is a relatively new thing on Canon digital SLRs (I believe it was introduced with the 40D), whereas Nikon owners have had the feature for a while.

I don't believe that Canon has built-in, in-body image stabilization (IS) either, in any of their digital SLRs. If you want IS, you need to buy a Canon-compatible lens with IS.
posted by kathryn at 9:43 AM on September 3, 2008

Check out The Strobist and learn how to use flash.
posted by alidarbac at 9:46 AM on September 3, 2008

I would suggest that if you're in restaurants and such, where lighting won't change much:

Meter on faces using AV mode at ISO 1600 and f1.8.
Once you get a shutter speed, switch to manual and put in f1.8 and the shutter speed.

This way, you'll get consistently exposed photos for all and you can batch process your photos all the same and save some time.

You're doing great. Experiment with the lighting to create mood.
posted by inviolable at 10:26 AM on September 3, 2008

is there something I'm missing in the technical details
Does Aperture have presets? I've built a library of Lightroom presets (WB, sat, curves, sharp, NR) so that I do minimal adjustments. Also, I often copy the adjustments from one photo onto the rest in a single shoot since many times fairly similar adjustments are required to all the photos in the same shoot.

criticism or tips on better low light shots
1. Turn off bracketing/AEB and do 3-shot bursts. Usually the 2nd or 3rd one will be spot on sharp. As long as your meter off the face, AEB shouldn't be necessary in RAW.
2. Looking at your 3 photos, there's softness in the wrong places (eyes). Autofocus systems often lock onto the nose or cheekbones with glare -- you'll want to refocus or recompose for the eyes.
3. Buy a flash. For a long time I stayed away from a flash because I didn't want that "strobed" look. But when used properly you'd never know it was there until you compare with others who didn't use flash.
4. Lift weights (dumbbells) in slow reps.
posted by junesix at 2:34 PM on September 3, 2008

Great photos!

Just a note: I own both the XT and the 50mm f/1.8 lens and I find that the XT's AF doesn't work very well with the f-stops of lower than 2.8 or so. Essentially, in my experience, the camera's AF points thinks it's focused but may actually be front- or back-focused due to the narrower depth of field of the larger aperture triggering the AF prematurely. A better explanation may be found elsewhere -- in general, you may not be able to use the best aperture setting you have on hand for your low-light pictures. (I think this may be especially true for the candlelight photo.)
posted by popsciolist at 1:57 AM on September 8, 2008