Technically it can use anything from goPro, iphone, compact, full dslr
It really depends on your purpose.
A top quality DSLR will give best results, but if your computer/gpu isnt strong enough to process the large images then you dont benefit. So in this situation if you want the best you can get its Camera+system sombination.
For a lower level than a top range camera, Im using the new sony rx100M3. Its small, light, makes a good picture, and easy to put on extension poles or copters. I can recommend it UNLESS you want to use photoscan pro and use GPS info, as this camera doesnt store GPS data
I have a canon D1100 also which is a fairly entry level dslr, but takes a nice photo also..and it came with 2 useful lens if you need to do some zoom photography (I do environments, so the ability to zoom a bit is useful)
Together with the rx100M3 its a nice combination of detail, clarity and portability.
I have 2 9xx series GPU cards and 32GB ram to crunch the info. My last photo recon of a cliff had a result of 1700 photo. Im aligning now (takes over night each attempt)
I also threw in a Canon s100 as that one has GPS and can hopefully lock the whole set to a world space since the other 2 cameras dont have GPS
-P