Digital Photography 101: Low-light photography, part 1

Don't get caught in the dark -- the basics of low-light photography

Digital Photography 101: Low-light photography, part 1Just about every modern camera has some sort of flash, but that doesn't mean that you will get very good results by using it. Between the dreaded red-eye and subjects looking washed-out and pasty, you're generally much better off not using the flash at all. Taking good photographs in low-light situations without using a flash takes practice and a bit of technical know-how, but it can be done!

It's worth noting that "low-light" does not necessarily mean "nighttime" -- we're using that term to refer to any situation in which the camera might decide it should use the flash. That could also mean indoors on a cloudy day, or under a thick canopy of trees, or at dusk or dawn. In part 1 of our low-light photography series, we'll discuss the basics of how to take good pictures when the lighting is less than ideal.

kmg 300 low light pumpkinsTake it off automatic
First things first: Take your camera off the auto setting. Auto is meant to be as general as possible, and it will assume that if the light is low, you want to use the flash. But as we've already discussed, you don't! So take the leap, be brave, and use a different setting. Which setting to use? The best solution will depend largely on the specifics of your scene. For now, just try using the flash off mode. This will probably be indicated by an icon that looks like a lightning bolt with a line through it. 

What you need to bear in mind when using the flash off mode is that the camera will still try to choose the best settings for the light that you have -- but more often than not, it won't choose correctly. By default, if you simply turn off the flash, most cameras will adjust to a much slower shutter speed to accommodate the lack of light. If the shutter speed it chooses is too slow, the resulting image will likely be blurry. 

How do you prevent this from happening? Check your camera's display -- it will tell you what shutter speed it's using. If it's slower than 1/60th of a second, then you should either adjust your settings or use a tripod.

kmg 630 low light candle flickr toddyoungUse a tripod
One of the things we've mentioned many times is that a tripod is essential when you're shooting in less-than-optimal conditions. The most steady-handed human can't hold a camera still enough to get a sharp image at shutter speeds slower than 1/30th of a second. 1/60th is a much safer bet. If you're using a larger, heavier lens, however, you'll have to use an even faster shutter speed to avoid motion blur -- unless, that is, you use a tripod. 

Tripods have come a long way in terms of convenience, and are much lighter, faster to set up, and easier to use than they used to be. Still don't want to lug around a big tripod? Try the Gorillapod, which can wrap around just about anything and provides enough stability for even most DSLR cameras. 

kmg 300 low light birthday cake flickr jessecourtemancheTurn up the ISO
ISO is a measure of how sensitive your film is, or if you're using a digital camera, how sensitive the camera's sensor is. A high ISO means that the sensor is picking up much more light, which means that you can use a faster shutter speed and not end up with a black, underexposed picture. So the easiest way to compensate for low-light situations is to change to a higher ISO setting on your camera. Be aware, though, that the higher the ISO, the more digital "noise" you'll have, which means that the resulting photograph will be grainier and not as sharp when you enlarge it.

Open the aperture
Aperture is the term for the actual opening that lets light onto your film or sensor. The aperture sizes are referred to by f-numbers, which actually refer to the ratio of focal length to effective aperture diameter. That's why the numbers are somewhat counterintuitive -- the larger the number, the smaller the actual opening. So to allow more light to reach your sensor (thus allowing you to use a faster shutter speed and lower ISO), use a wider aperture with a small number such as f/2 or f/4. 

Keep in mind that the size of the aperture also affects your photo's depth of field (the range where things are in focus). The wider the aperture, the smaller the depth of field. This means that if you're photographing a night cityscape, where it's important that elements at various distances all be in focus, you'll need to use a smaller aperture.

kmg 630 low light sofa laptop
Balance the trade-offs
You might have noticed by this point that low-light photography is all about trade-offs. You need to balance the sensitivity of high ISO with the need to reduce digital noise. Balance a wide-open aperture with the resulting small depth of field. Usually, the optimal solution will be some combination of shutter speed, ISO, and aperture settings.

The best way to learn how to balance all these elements is to experiment. Use bracketing to try out the same scene with different settings -- try it at 1/30th, 1/60th, and 1/100th of a second, or use f/2, f/2.8, and f/4 apertures, and see what looks best. Make use of whatever light you have. That might mean moving your subject closer to a window or using a table or overhead lamp to provide greater illumination. Keep practicing, and you'll find yourself taking beautiful photographs without ever thinking of using the flash! 

[Writing Credit: Katherine Gray.  Image credits: K. GrayTodd YoungJesse CourteManche]

Thanks to our friends over at Tecca for submitting this post, and keep your eyes peeled for more parts in this series.  Find more How-to tech articles & Gadget news at Tecca.com.  And, as always, if you have any low-light photos, post 'em on Steve's Facebook Wall, or hit up the Steve's Forums to talk about this article, ask questions, or anything photography related.