i feel like a fish eye would affect the quality. is this true?

 

I haven't noticed a real difference in quality between using just my 18-55 compared to my 18-55 with the fisheye on it; obviously there's the distortion around the edge of the lens, but that's kind of the point of a fisheye. Granted, I'm not that great of a photographer, so with a better photographer you might see more of a difference. And hopefully this weekend I can get my car all nice and clean and go on a photoshoot; if that happens, I'll have wide-angle pics for you guys

 

Canon XTi
-BG-E3
-vivitar 285hv x2
-sigma 18-125mm F/3.5-6.3
-cactus v2s receiver and transmitter
-various stands and umbrellas

 

Body: Canon 7D
Glass: Sigma 18-250
Flash: Canon 430EX II for use mainly as an off-camera flash
Two tripods.

For now that's it.