The pictures are most likely in a folder named DCIM, and in there, in a folder named Camera. (I made a similar setup on my SD card - DCIM/Camera) to keep pictures, and set the camera apps (I use a few - some are better at some things than others) to use that folder. (The phone has to be rooted to have more than one app save to the same folder.)
You should also, while you're working on pictures, back up any important ones to your PC and/or to a cloud account or two. ("Too many backups" is just words that don't mean anything - you can never have too many.)