Very, very impressed by the Canon 8-15

rowlandw wrote:

Tnx for that - I prefer wide angle and have the Canon 15 fisheye, Canon 17-40, Sigma 8-16 for crop, Rokinon 14 and now the Tamron 15-30 which is good at avoiding distortion and flare, and is very sharp. (One reason I got the Tammy is it has the best handholdability in low light (15mm-IS-f/2.8) and it feels like holding onto a fixed object.) I too thought the wide end of the 11-14 was a bit extreme re: the corner distortion you mention (as well as the cost). Based on your post I'll probably rent the 8-15 for a better look.

On crop, think of it like this (these are approximate):

• 8mm=8mm rectilinear
• 9mm=10mm rectilinear
• 10mm=12mm rectilinear
• 11mm=14mm rectilinear
• 12mm=16mm rectilinear
• 13mm=18mm rectilinear
• 14mm=20mm rectilinear
• 15mm=22mm rectilinear

As I said, 16-18mm is about my limit for rectilinear, so I'd try not to fully defish if I'm below 12mm on a crop camera.

Another thing I've been doing a lot lately is using Lightroom's geometric distortion slider in the profile.  You can set it to anything from 0 (no correction) to 200 (twice the nominal correction, which is 100).  I've routinely found that full-frame fisheye shots look best in the 20-70 range which is notably not at 0 and not at 100, which are the two ways most people think of a lens (fisheye or rectilinear).  Yes, some shots are best at full rectilinear, but not at 15mm on full-frame or 9-10mm on crop.