Why mirrorless? For your use--"amateur cat photography at a shelter"--I don't see any advantage to a mirrorless camera over a DSLR. Given that, and the fact that budget is a concern, I'd recommend an older entry level DSLR from Canon or Nikon and a 50mm f1.8 lens.
My 2¢ - Mark
Hello, I need help choosing an interchangeable lens compact for a specific need: cat photos. I volunteer at a shelter in Italy and take the pics for : adoptions (web and paper flyers), the assoc.'s print materials - calendar, flyers, posters.
I've been using a Ricoh R10 (a compact with travel zoom) since 2009 and wanted to go reflex & get the Nikon D3100 on sale. Saw what's on the market now and am considering the Sony Alpha NEX 5N. Saw a review for the Canon EOS M (too expensive) at reviews.cnet.com/digital-cameras/canon-eos-m/4505-6501_7-35401433.html. The cameras listed in the comparison are the ones I've been looking at! Have not been able to find a review for ILC's and cat photography.
Model suggestions /comments for my needs?
I'd like to beautify my photos, since I take so many pics of cats (Mine, sheltered, strays). I don't like using the flash. But indoors, in cages it's almost obligatory.
At school, I did B/W printing in the darkroom. My first electronic camera in the '80s was a Minolta 7000, very bulky and cumbersome (it was dial free, and you had to wait a week for film to be developed!). When 35mm went digital, I went point&shoot.

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