Cameras

1988: Canon EOS 650

•Price: $600 ($1052 adjusted for inflation)

•Format: analog 35mm film

•Capacity: 36 shots

•Preview: optical viewfinder

•Speed: 1/2000 shutter and 3-fps auto advance

2008: Canon EOS Digital Rebel XTi

•Price: $600

•Format: 10MP digital JPEG

•Capacity: determined by CF Card

•Preview: 2.5-inch LCD and optical viewfinder

•Speed: 1/4000 shutter and 3-fps for up to eight shots

The price and the looks of Canon's entry-level autofocus SLRs haven't changed much in 20 years — but with the switch from film to digital images, the technology certainly has.

The EOS 650 was the first in Canon's EOS line, and it introduced the first fully electronic lenses. Amazingly, those EF (Electro-Focus) lenses are still usable on today's digital EOS models.

The 650 had spot-matrix metering — a big advance at the time — and a convenient mode dial that lives on in the EOS Digital Rebel XTi.

But of course film is utterly different from digital images, and it took a long while for the resolution and speed of digital SLRs to roughly equal those of 35mm film. Now that parity has been achieved, the convenience of digital has knocked the bottom out of the film market.

The latest advance that should make its way down to consumer digital SLRs involves full-frame image sensors. These sensors are the same size as 35mm film, allowing photographers armed with DSLRs to use lenses designed for analog SLRs to full advantage.