Circular fisheye fall off

[Ben Kreunen <ben@xxxxxxxxxxxxxxxxxxxxxxx>]

Here is my test image <http://www.bigbenpublishing.com.au/demo/ir1.jpg>

Fall off is most noticeable at the bottom and lower left. And then of 
course there was the exposure difference and sharpness. Contrast has been 
matched between the images for bright area of brick paving and shadows on 
the right, sharpness at this size is not that noticeable, but trust me on 
this one.

Also the image circle did get a bit smaller as I stopped down but this did 
not appear to alter the magnification. I would have to confirm this with a 
tripod mounted test but remapping the image to an equirectangular 
projection produced no significant change in magnification that I could 
see, just some cut off of the image. A change in magnification could 
present a problem for my specific application as I would have to calibrate 
the software for each aperture which could get messy.

Equirectangular image???  <http://www.bigbenpublishing.com.au/demo/ir2.jpg> 
shows a fisheye image and it's remapped appearance.  Equal angles 
horizontally and vertically, like a rectangular map of the world...  or 
<http://www.bigbenpublishing.com.au/victoria/virtual/vr/mu001_ir.jpg> for a 
complete spherical panorama...  1500x750 pixels = 360x180° (4 1/6 pixels 
per 1° in horizontal or vertical direction)

Cheers

Ben

===========================
http://www.bigbenpublishing.com.au/
===========================

*
****
*******
******************************************************
*  To remove yourself from this list, send:          *
*         UNSUBSCRIBE INFRARED                       *
*       to                                           *
*         MAJORDOMO@xxxxx                            *
*----------------------------------------------------*
*   For the IR-FAQ, IR-Gallery and heaps of links:   *
*  http://www.a1.nl/phomepag/markerink/mainpage.htm  *
******************************************************