Rectilinear: FOV = 2 atan (image size/(2*focal length)) Fisheye: FOV = 4 asin (image size/(4*focal length))
Given 35mm film size of 35.8x24.3mm, and the -DS sensor at 23.5x15.7mm, you get these numbers (in degrees X by Y landscape mode):
20mm Rect: 83x63 (35mm), 61x43 (1.5 crop) 14mm Rect: 104x82 (35mm), 80x59 (1.5 crop) 16mm Fish: 136x89 (35mm), 86x57 (1.5 crop)
So, what I *meant* to say is that FOV of the fisheye is about equivalent to a 13-14mm rectilinear lens on the -DS, or a 20mm rectilinear lens on a full-frame 35mm body.
-Cory
On Sat, 23 Apr 2005, Shel Belinkoff wrote:
Huh!
I've used a 16mm Zenitar, an 18mm and 20mm Pentax on a 35mm camera. The Zenitar isn't a 20mm ... it's CONSIDERABLY wider than the 20mm and the 18mm. How do you arrive at the conclusion that the 16mm Zenitar equates to 20mm coverage on 35mm?
Shel
On Sat, 23 Apr 2005 11:31:44 -0400 (EDT), Cory Papenfuss wrote:
Anyway, the 16mm Zenitar fisheye can be had for $100-$150 and equates to about 20mm coverage on a 35mm, or 13-14mm rectilinear on a 1.5 cropped body.
************************************************************************* * Cory Papenfuss * * Electrical Engineering candidate Ph.D. graduate student * * Virginia Polytechnic Institute and State University * *************************************************************************
