Hi All of this indecision about which image axis to link to "fov" is unnecessary and misleading, because fov is properly a secondary quantity, derived from the following primaries: focal length (in pixels); image width (ditto); lens projection function (angle vs. radius).
A sensible image processing program would show you the fovs on both axes, or indeed in any direction you choose. I'll repeat. If you don't like to think about focal length, or the idea of measuring it is pixels repels you, you don't have to think about it at all. The EXIF data from all modern cameras supplies the necessary information, and your stitcher knows how to interpret that (well maybe not PTGui, see below). And in case you have a camera that does not report focal plane resolution, you _should_ only have to enter its sensor dimensions or crop factor once, and your stitcher _should_ be able to fetch that out of its camera data base or preferences table from then on. Hugin developers take note. On Jul 20, 12:33 pm, Bruno Postle <[email protected]> wrote: > On Mon 20-Jul-2009 at 07:53 -0700, Bart van Andel wrote: > > > > >Maybe FOV should be treated differently based on the lens type. This > >does make sense, as for circular fisheye the given (or guessed) fov of > >the lens is only the fov of the circle, not of the full frame. > > This is how ptgui does it. I've noticed that. And I just noticed something else odd about PTGui: it gives a bogus crop factor for my Canon EOS 30D. The correct crop factor, according to the EXIF focal plane resolution data, is 1.60149, which is what Hugin 0.8 reports. But PTGui 8.1 says it is 1.5870. I suppose this must be a bug, and have reported it on the PTGui support board. > > Hugin does it the right way: the 'crop circle' for a circular > fisheye simply indicates the outer area of the frame that should be > ignored when rendering, it is unrelated to any other lens > parameters. > But PTGui computes fisheye fovs according to the equal-area formula, while Hugin still uses the inappropriate equal-angle formula (so does PTAssembler 5.1). Regards, Tom --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "hugin and other free panoramic software" group. A list of frequently asked questions is available at: http://wiki.panotools.org/Hugin_FAQ To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/hugin-ptx -~----------~----~----~----~------~----~------~--~---
