Low light causes problems for photographers. Let's solve them.
February 18, 2008
So-called "high-resolution" compact cameras (8MP and up) and low light are a recipe for disaster, as illustrated in the photos below. (The technical explanation follows.)
Shot at ISO 800 with an 8-megapixel DSLR, no flash: Clear, sharp, with accurate color and good contrast. No problem here. Photos by Mason Resnick
Same scene, shot at ISO 800 with an 8-megapixel compact camera, no flash: A bit hazy, thanks to light spillover between tightly-packed pixels. But wait…it gets worse!
Compare details from the DSLR version, left, and compact camera image (right): a sharp, accurate image, versus a blurry, mottled, splotchy mess! And at 9-12 MP, image degradation in compacts is even more pronounced.
Compact cameras use really, really small sensors to capture images. To squeeze all those pixels onto such a small sensor, something has to give. Each pixel is like a microscopic lens, and each pixel is separated by a little wall, called a Septum. The septum is supposed to keep light from falling over from one pixel to another. But to make room for more pixels, the septums have been removed from high-resolution sensors. This causes lower contrast and digital noise (AKA grain). You may be able to make big blow-ups with your 12MP compact, but they won’t look as good as manufacturers want you to believe.
Even worse: Boosting the ISO, which is recommended when shooting in low light without a flash, amplifies the noise. It’s like boosting the gain on a guitar amplifier. While you might want that kind of distortion when playing the opening notes of "Satisfaction" on your Stratocaster, you don’t want it in your photos.
The bottom line? If you shoot a lot in low light without flash and you want to make big prints, invest in a DSLR.