Convince lens manufacturers to provide calibration data

[Donatzsky (Nis Donatzsky)]

@Vente

Nikon cameras include image correction coefficients in EXIF, but they’re in a format not recognized by Darktable. If we had the algorithm for how these values work, a lot of lenses would be covered at once.

The relevant discussions:

Reverse engineering Nikon Z-series lens correction

The new-ish Nikon Z series of cameras and lenses contain distortion and vignette correction in each raw file, the same as other manufacturers such as Sony and Fuji are doing. The upside is that you don’t need to profile every lens for inclusion in lensfun anymore, it the downside is that we will need to reverse engineer what that metadata means and the formulas used, as like other manufacturers, Nikon hides this information behind an NDA. And NDAs and FOSS code do not go together. Actually I d…

Reverse Engineering Nikon Z series lens correction - Part 2?

I’m starting a new thread because the forum won’t let me post three consecutive posts… Oookay, did some close inspection of my code and found a parentheses error in my calculation of the adobe normalization, fixed that and the dng numbers @paolod supplied correct the image just fine… With that and some inspection of extracted values, I determined that if one uses the adobe model and feeds it the metadata coefficients in reverse order, the correction is quite clos…