A useful lens calibration database has to identify the lens, and the camera sensor format (physical pixel dimensions). It is a sad fact that EXIF data often don't identify the lens, especially if you use 'foreign' lenses; and that what ID there is is largely manufacturer- specific. And though the EXIF always identifies the camera, more often than not it doesn't specify the sensor dimensions (among the majors, only Canon consistently does this -- but it is not always right for alternative image formats such as video).
Consequently I think it is a mistake to put too much effort into deconstructing EXIF files, and trying to make a 'universal' database. Instead, we should aim for a personal database that 'learns' to correctly guess the lens and pixel size based on what a given photographer actually uses, using EXIF data and image dimensions, and resolving uncertainties by having the user select from short, relevant lists of possibilities. I could live with that. Of course, given a suitable standard for portable lens calibrations, such a system could still free the average user from having to calibrate his own lenses. Adobe's 'lens profiles' scheme works well for both fisheye and normal lenses, and since it is an open standard, we could use it too. And get the benefit of a big base of published calibrations. It is presently hampered by a rather difficult calibration program and by a less than fully useful implementation of lens corrections in ACR; however the calibration data format is perfectly sound and could support other correction software and other calibration tools. Or we could use my "ULM". The important things are to get reliable transfer of usable calibrations from originator to user, and to support all lenses, including fish-eyes. HAPPY NEW YEAR --Tom On Dec 23, 11:18 am, kfj <[email protected]> wrote: > On 23 Dez., 14:25, "T. Modes" <[email protected]> wrote: > > > > Is the Samyang 8mm stereographic fisheye already in the database? And > > > if so, what is the > > > string used to identify it? > > > No. Currently there are only 2 fisheye lenses in the database. > > Okay. Make it two more then: > > "Samyang 8 mm f/3.5 Aspherical IF MC Fish-eye" > "Walimex Pro Fisheye 8/3.5" > > seehttp://www.lenstip.com/160.11-Lens_review-Samyang_8_mm_f_3.5_Aspheric... > > AFAIKT these are both the same lens, I bought mine as Walimex from > Amazon in Germany. If you think the strings are too long, feel free to > propose shorter versions - after all, since the lens name has to be > patched into the EXIF data we're free to choose whatever we want ;-) > > I use the lens with projection set to stereographic, which seems to > fit fairly well. Is this all you need, or would you like lens > correction coefficients as well? > > 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 [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
