Well, you can read all the numbers about fov and angles etc. like in this
thread, but our new forum-member skelter asked for a real life view of the differences between a fisheye, namely the Tokina 10-17mm fisheye-zoom and another ultra-wide zoom like the Sigma 10-20mm.
As I don't have the Tokina 10-17mm handy I took my trusty Nikon 10.5mm fisheye out on this great day and made 2 shot from the same point of view with both lenses to compare. And I also threw in a defished version of the fisheye-pic for good measure. These defished versions were made in CaptureNX, but a word of warning here: I don't think (but cannot test) that CaptureNX will defish other than Nikkor lenses. So when defishing a Tokina 10-17mm e.g. you have to rely on third-party software.
So here are the results (all pics clickable for larger views):
|----------Nikon 10.5mm original--------||----------Nikon 10.5mm defished--------||--------Sigma 10-20mm at 10mm-------|
As you can see the defished fisheye is still wider than the "straight" 10mm but the edges have visibly lower IQ.
Thomas (beware: Nikon-fanboy and moderator!) My Lens Reviews
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