what is a digital SLR, anyway?
The term digital SLR is short for digital single lens reflex, so named because these types of cameras use a mirror positioned behind the camera lens to direct light toward the viewfinder when you’re composing a photo. When you release the shutter, the mirror swings quickly out of the way, letting light from the lens travel straight to the sensor and momentarily blacking out the viewfinder. The viewfinder in an SLR incorporates a prism–usually a pentaprism–that flips the incoming image around so that you can see it right side up and bounces it onto the focusing screen where you see it. The SLR design allows one camera to accommodate a very wide range of lens focal lengths, and that’s the biggest reason that SLRs dominate serious photography. The explanation? With a non-SLR camera, you have to match the angle of view of the “taking” lens with that of the “viewing” lens. That’s easy with a fixed lens or a short-range zoom, but it requires increasingly complex and expensive viewfinder me
