Hello Karl, I am aware of this thread, but it does not match my experience: there is almost no vignetting in the viewfinder with my unmodified 60-250, which means that it is pixel vignetting. Anyway, my goal is to be able to compensate that vignetting with lensfun. Regards, Louis
> Le 4 déc. 2016 à 16:43, Karl <lens...@northsun.ca> a écrit : > > Hi Louis, > > Greetings from a fellow Pentaxian! :) > > As discussed on > http://www.pentaxforums.com/forums/10-pentax-slr-lens-discussion/304092-da-60-250-mod-ff-9.html > > the vignetting for this lens is caused by a mechanical baffle at the > rear of the lens, and so the vignetting you're experiencing is likely > not caused by sensor design. > > Several people have reported successfully removing or modifying the > baffle, which fixes the vignetting with little to no reduced image > quality. Samples here: > > https://www.flickr.com/photos/72309835@N02/sets/72157666809541434/with/26902896134/ > > -Karl > > >> On 12/04/2016 01:42 AM, Louis Granboulan wrote: >> Dear all, >> >> I use a "smc Pentax-DA* 60-250mm f/4 ED IF SDM" on a "Pentax K-1". >> This lens is not designed for full frame, but its only drawback is a strong >> vignetting. >> This vignetting does not show in the viewfinder, it only shows on the >> sensor, which means it is "pixel vignetting". >> Pablo d'Angelo's paper does not take into account pixel vignetting, and one >> consequence is that lensfun cannot optimally correct this vignetting. I can >> provide example pictures if you want to check this impossibility statement. >> >> I propose to work on adding to lensfun the possibility of using another >> formula, with more parameters (higher degree polynomial). >> If I do this addition, will it be integrated in the library, so I will not >> need to maintain a homemade patch? >> >> Regards, >> Louis >> ------------------------------------------------------------------------------ >> Check out the vibrant tech community on one of the world's most >> engaging tech sites, SlashDot.org! http://sdm.link/slashdot >> _______________________________________________ >> Lensfun-users mailing list >> Lensfun-users@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/lensfun-users > > > ------------------------------------------------------------------------------ > Check out the vibrant tech community on one of the world's most > engaging tech sites, SlashDot.org! http://sdm.link/slashdot > _______________________________________________ > Lensfun-users mailing list > Lensfun-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/lensfun-users ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, SlashDot.org! http://sdm.link/slashdot _______________________________________________ Lensfun-users mailing list Lensfun-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/lensfun-users
