DSLRs have some unique challenges when shooting green screen, but have some advantages over video.
1- DSLRs use a compressed format - keep you ISO low, keep your light bright. We found fluorescents particularly useful, but you need a lot of them. Light the hell out of the green screen. It should be bright enough to shoot by itself at ISO 100, shutter between 1/60 and 1/125, with an f-stop around 5.6 - I don't recommend higher (found it better to limit DOF to keep the green screen out of focus unless you are tracking points, but that's another story). You will light your subject separately and will need another set of lights to do it.
2. A narrow DOF is your friend and foe. If your shooting at an f2.8, you get lots of light, but also fuzzy edges. Now you have to hope you have the software to handle pulling the matte.
3. Green gets everywhere. It reflects into the shadows, appears in the highlights, wraps around the subject. You get the idea. Since it sound like you only have the one side, this may not be an issue, but be looking for it.
4. Did I mention you need lots of light? I like fourescents because they provide even light on the green screen, then you need to light your subject separately. I like daylight balanced cfls and daylight balanced tubes. The tubes are great for the screen mounted above and pointed down and towards the green screen and then use cfls and/or tubes to light your subject. Did I mention they should be balanced? I like daylight balanced.
5. Covert. Transcode. The native file format can be dodgy. Prepare to trancode to an editing format like prores 422 for apple or cineform for PC - I think, I'm not a PC person anymore.
All that said, it is possible to use a dslr to shoot green screen. Is it as easy to do as a regular (non dslr) camera? Yes and no and it depends on what you have and know already. Plenty of people are doing it, but I suggest using a film workflow rather than a video workflow. You mentioned being a photographer and wanting an easy key - the suggestions above will help, but practice will make perfect.
Jonathan Ziegler
http://www.electrictiger.com/
520-360-8293