Hi there… I used a nikon d3100 with the 18-55 lens for all my cakes aside from a few shots on my last set, where I had a new nikon d3200 with the same lens. I think it’s important to get a camera as opposed to using a phone if you hope to use some of your images in print- either for yourself or mags – because the resolution probably won’t be good enough from a phone. If it’s just for the Web, you can get away with pretty much any camera, but for anything point and shoot you will only get high quality shoots in bright conditions.
I also can’t stress the importance of nice backgrounds enough, or clear detail shots. Most people will ignore even the most beautiful cake in a poor photo with clutter everywhere, poor lighting and a lack of clarity in the details. You can pick up a good enough dslr for 200 used to 300 new, well worth the investment if you’re hoping to gain business.
Best wishes xx