I'm sure most, if not all of us, take photo at conventions, but they are not the only option for cosplay photography.
Over the years, I've gone to some local meetups where cosplay is involved. These can be just as fun and rewarding compared to conventions. Some are large in the 50 people range, others just a handful. These are great for doing more elaborate lighting setups, or just getting some recreational/experimental photography in. The last one I went to was a small group meetup at an apple orchard
where I used a small digital camera instead of a SLR.
What I haven't done much are private sessions with a single cosplay model or two outside of conventions or meetups/gatherings. More for the reason of few cosplayers that I know of in my city.
So what type of situations do you take cosplay photos?