Swampfoot
15th of May 2003 (Thu), 23:17
I just got me a Kenko wide angle lens to go on my Canon S10, (via the CKC Power 37mm thread adapter). Around the lens rim it says "Kenko DIGITAL Fisheye 0.43x"
I wanted to do QTVR shots with a greater field of view than the 35mm equivalent lens on the S10 alone would give. I have been making QTVRs with the S10 using QuickTime VR Authoring Studio for several years now with good results. Since the new Kenko lens is a fisheye, the images taken with it will have to be remapped to rectilinear using a separate program before bringing them into QTVRAS.
Two bits of data that one needs to use this remapping software are the focal length and field of view of the lens. Niether was provided in the documentation with the lens, only that it is "0.43x."
I did try measuring the FOV of the lens by hanging a black string on a blank wall as a plumb line, and panning my camera to one side after centering the line in the center of the viewfinder using a radial sighting system I threw together.
The plumb line went out of view at 70 degrees of pan, or something very close to it. So that would mean a total FOV of 140, I think?
Does anyone know how to compute a focal length or FOV of a lens when you don't have either of those numbers, only its magnification (in this case 0.43x)?
Thanks!
I wanted to do QTVR shots with a greater field of view than the 35mm equivalent lens on the S10 alone would give. I have been making QTVRs with the S10 using QuickTime VR Authoring Studio for several years now with good results. Since the new Kenko lens is a fisheye, the images taken with it will have to be remapped to rectilinear using a separate program before bringing them into QTVRAS.
Two bits of data that one needs to use this remapping software are the focal length and field of view of the lens. Niether was provided in the documentation with the lens, only that it is "0.43x."
I did try measuring the FOV of the lens by hanging a black string on a blank wall as a plumb line, and panning my camera to one side after centering the line in the center of the viewfinder using a radial sighting system I threw together.
The plumb line went out of view at 70 degrees of pan, or something very close to it. So that would mean a total FOV of 140, I think?
Does anyone know how to compute a focal length or FOV of a lens when you don't have either of those numbers, only its magnification (in this case 0.43x)?
Thanks!