Hi Jolyon & Cedric!

I’m able to get pretty high R^2 values for UV+VIS camera calibration (R^2 >0.98) using a pastel “chart”, but I must be scaling my spectra incorrectly, because the output cone catch images are always incredibly grey/washed-out. Cedric helped me realize earlier that my processing in pavo (I was averaging multiple spectra for each pastel together) was doing a negative value correction (“addmin”) that was causing my values to exceed 100, but now that I\’ve fixed that and have 0-100 range for my spectra files, I still have the same problem. I’ve tried every combination of negative value correction and scaling I could come up with (0-100 scaling for % reflectance, 0-1 scaling for normalized reflectance per the XRite spectra that come with micaToolbox, and all the different negative value correction options for processing in pavo including leaving them in), but still run into the same issue.

I was wondering if you have an example of the pastel spectra & mspec image that were used to make one of the UV camera calibrations that come with the package, so I could see where I’m going wrong? Alternatively, if anything from my above description sounds like we’re approaching this problem wildly wrong, that would also be great to know…so close to finally getting this calibration to work!



Pastel calibration – example spectra file?
Hannah Unselected an answer December 10, 2021