I'm finding that this is a great lens for aquarium photography. It's a heck of a lot sharper than my kit lens, and it's a lot faster at 50mm (f/2 vs f/5.6) which gives me a lot more options for shutter speeds and ISO.
Dueling Saulosi
Smiling Rusties
A male and female acei
And the king of the tank, a male Red Empress This one was taken with the 2x teleconverter. It's kind of soft, but I think it makes for a cool fish portrait






Very nice, wish I had your equipment and skills
