Canon 15mm f.2,8 degrees?

[Ortved]

The Canon 15mm f.2,8 is said to give 180 degrees on a FF sensor, does anybody know how many degrees I’ll get on a 350D/1D mkIIN?
Respective I’ll get 24mm and 19,5mm when the focal length is converted, but what about the degrees?

Ortved

[steved110]

It gives 180 degrees diagonally - it is not a circular fish eye. It distorts very strongly but used with care can render striking images.

On a crop camera you will simply see less of the distortion as the sensor only uses the central portion of the image, and the distortion is greatest at the edges of the lens.

Exactly how much, i cannot say. I'm not that mathematical!

But if i wanted a fish eye I'd be looking at the Peleng - it's manual focus but the dof on these is vast so focusing is almost irrelevant. do a search - there are a number of threadss showing examples of the peleng and othr fish eyes.

[Madweasel]

The Canon 15mm f.2,8 is said to give 180 degrees on a FF sensor, does anybody know how many degrees I’ll get on a 350D/1D mkIIN?
Respective I’ll get 24mm and 19,5mm when the focal length is converted, but what about the degrees?

Ortved
On a true fish-eye, the angle is linear with distance in the image. What this means is that it will be a very good approximation to use the crop factors, so that the 1D MkIIN would give you 180/1.3 = 138 degrees, and the 350D would give 180/1.6 = 112 degrees. As Steve says, the strongest part of the fish-eye effect is noticed at the outer parts of the image, so much of the effect is lost in the crop, especially 1.6.