Sigma 4.5mm F2.8 EX and 10mm F2.8 EX "FISHEYES" Announced

With the lens cap on the 10mm is the largest of the bunch but without the lens cap the 4.5mm is slightly larger. I wish both were more the size of the 15mm because that one is so easy to stick in a small bag for a day's shooting.

I wonder if that War of the Worlds thing comes in a Canon mount....

tiktaalik wrote in post #4947632
I wonder if that War of the Worlds thing comes in a Canon mount....

No, but it didn't give good resolution anyway

is the fixed 10mm sigma wider than 10mm on the sigma 10-20mm?

if so..why?

Yes, the Sigma 10mm fisheye is wider any 10mm rectilinear lens.

Rectilinear lenses see the world much like we do. Straight lines are rendered straight in the image. It is impossible to make a rectilinear lens with a field of view of 180 degrees. The 10mm rectilinear lens has a diagonal field of view of 107 degrees on a 1.6x crop body.

A straight line in a fisheye lens only remains straight if it runs through the center of the image. All other lines are rendered as curved. Fisheyes are designed to cover 180 degrees field of view, either along the diagonal (as with the 10mm) or along the horizontal and vertical (in the case of circular fisheyes).

(Note: a little fudge above. The Sigma 10mm fisheye was designed to fit a number of cameras and does not achieve true 180 deg FOV with the Canon sensor. At 167 deg though, it is still far wider than the rectilinear lens.)

This page has some diagrams and more explanation and a nice FOV calculator.

wow that's some crazy explanation, but good job either way =)