I just picked up the Sony A55 camera body. It is isn’t quite right to call it an DSLR as it isn’t really one, but it is close enough. SLRs have mirrors that allow the photographer to sight the photograph directly through the lens and when the button is tripped the mirror is pulled out of the way and photograph is recorded. Most DSLR style or class cameras have retained this. However, the Sony A55 has a fixed mirror that allows some of the light through to the exposure plane and causes a bit of the light to go to sensors that drive the view through the eyepiece or the screen.
Initially, that difference shied me away from the camera, but a big boss piece of glass — a 300 mm F/2.8 lens told me to get over those objections or else! That lens is one I purchased years ago for my Minolta Maxxum 7000i (film) camera. Of course my 50 mm macro, and a 70-210 zoom (all with a 2x teleconverter) joined in chorus and I finally broke down and bought the camera.