This is a question you will ultimately have to answer for yourself, but I will give you a few ideas to start things off. There is a lot to experience in the world of conventions, and more specifically how it relates to photography. It is a whole world that is partly hidden from the general public, and something which will give you a multitude of subjects to point your lens at.
In general every day life, photography has had a negative stigma forced upon it. Ask someone if you can take their photo in public, and you will probably garner a negative response. The average person sees photography in public as something foreign and also something to shy away from, or even try to prosecute in extreme situations! While we as photographers know there are certain rights available to us such as being able to photograph pretty much anything from and on public lands (in the USA mind you), we still can end up in bad situations thanks to ignorant people. In contrast, at Anime and Sci-fi conventions, the people dressing up in costume actually want to have their photo taken. Photography is a given in this culture and something to be happy for from the perspective of pretty much everyone who attends. You can be in your element and enjoy your hobby or profession to its fullest here. We want to take photos and they want their photo taken.