----- Original Message ----- From: "Mishka" Subject: RE: Mamiya fisheye
> fisheye with no distortion is no more oxymoron than rectilinear with no > distortion. > it is not possible to map 3d world as we see it (hemisphere) on a plane with > no distortion. > from this point of view, rectilinear is as bad as fisheye, just different. > when speaking of lenses, "no distortion" usually means "no deviation from > the idealized mapping", > for rectilinear being x=t*tan(theta), and for fisheye x=r*theta or > x=r*sin(theta). > Fisheye lenses are defined as follows: "A fisheye lens produces extreme barrel distortion and exagerated forshortening in the center" by the ICP encyclopedia of Photography, your funny little formulaes not withstanding. William Robb
