On 20 Apr., 19:24, Nathan Armer <nathan.ar...@gmail.com> wrote:
> On one of the 360 degree panoramas I made, > Hugin calculated the HFOV at 44.09334 degrees for every image (all > taken with my itouch). Can I trust this figure and use it to > calculate crop factor and 35mm equivalent focal length? I'd answer 'yes' to this question, provided you haven't made any grave mistakes during the take. I suppose you want to calibrate your lens for use with hugin, so you have a lens.ini file to use for new projects. For this purpose, the figure you get from a 360 degree panorama is perfectly sufficient. When doing a project based on this calibration, you may get away with reusing the values all the time, but often the stitch becomes better if you optimize for the values you have in your calibration as well, as slightly modifying them may mask slight imperfections in the take. But to have a good calibration is a valuable starting point, and since your lens is fixed there should be no or very little variation from take to take. (Simple devices do have advantages, as well :) On the other hand, calculating the FOV via the arcus tangens is a perfectly valid method (I haven't doublechecked if the link you posted points to correct maths). What isn't necessarily easy is to determine the NPP of your lens, so your distance to the reference surface may not be accurate enough to arrive at the proper figure. I'd say you're better off using your value derived from the 360 degree panorama. And if you do a few of these and see that after optimizing for FOV you arrive at the same value every time, you can confidently assume to have gotten it right. Kay -- 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 hugin-ptx@googlegroups.com To unsubscribe from this group, send email to hugin-ptx+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/hugin-ptx
