IPT
Active member
Looking to "expand" my collection of gear. I have a 20 mm Sigma that I like. I see that the 15mm has almsot TWICE the angle of view (180 degrees vs 91 degrees).
a - does anyone have these two focal lengths (full sensor body) and care to comment?
b - Seems like the Sigma is a "diagonal" fisheye and the Canon is not. What os the difference if any (the Sigma is actually $50 more than the Canon - I am not oppossed to paying more if it is for a good reason though I do like to have Canon gear I like my 20 mm Sigma).
LAstly, though I would like to grab a zoom they are too slow. I NEED F2.8 or faster for the Northern Lights.

a - does anyone have these two focal lengths (full sensor body) and care to comment?
b - Seems like the Sigma is a "diagonal" fisheye and the Canon is not. What os the difference if any (the Sigma is actually $50 more than the Canon - I am not oppossed to paying more if it is for a good reason though I do like to have Canon gear I like my 20 mm Sigma).
LAstly, though I would like to grab a zoom they are too slow. I NEED F2.8 or faster for the Northern Lights.
