Hi Terry, On 20 Dez., 04:48, "Terry Duell" <tdu...@iinet.net.au> wrote: > Hello All, > > I have a new camera and lens (Pentax K30-Sigma 18-200), and have been > testing a few things. > I find that Lensfun has two entries for this lens, I guess from different > contributors. >
Not fully correct. There are 2 entries for this lens in the database, one is for the lens mounted on cameras with 1.5 crop, the other one for the (same) lens on a 1.6 crop camera (other bayonet). I fixed it in the repository: it should now take also the camera (crop factor) into account when searching for lenses. I tested with your combination. Now it shows only one lens (I hope the right lens). > Following on the above results, I thought it might be enlightening to do > my my own lensfun calibration for this lens. > Reading the tutorial, the vignetting calibration looks a bit 'serious'... > for each focal length > for each aperture > for each distance > As I probably have about 7 focal lengths for this lens, and ?? apertures, > the cases start to mount up. > Is it really necessary to cover so many cases, or can hugin get by with a > smaller sample? I know that the vignetting depends on focal length and aperture. Often the vignetting becomes lower if the aperture is closed. I can't assess how the distance influence the vignetting. In the database there are only for some lenses vignetting data saved. Often it contains only data for different focal lengths and different apertures. Only 2 lenses (in mil-sony.xml) have data depending on all 3 parameters. So I would starting with only with different focal lengths and different apertures and see how it works. (Attention: Lensfun 0.2.6 contains a bug in interpolating the vignetting data, it is fixed in the svn repository, rev. 191). > > Finally, what units is 'distance' in the lensfun database...I can't find a > definition anywhere. I assume it is metres, but that could be wrong. > It should be meter. The unit should be appear behind the text box (in Hugin). Hugin is using the EXIF tag 0x9206, which should contain the subject distance in meter - at least according to the EXIF spec. Thomas -- 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
