SSF profiles in photon units (QE) or radiometric units?

[sschmaus]

I understand that absolute units are not needed to generate a color profile, but there is still a big difference between the two for this application.

Quantum efficiency (QE) just considers the conversion efficiency of a photon into a photoelectron. On the other hand, Radiometric units consider the actual energy carried by a photon at a specific wavelength, with short wave photons carrying more energy than those at long wavelengths.

Here is an example of the difference from the CMV-20000 sensor datasheet :

Notably, this changes not only the relative scaling between the filters, but also affects the location of the response peak, accentuating longer wavelengths.
More information about the difference: https://scientificimaging.com/knowledge-base/quantum-efficiency-spec-res/

Since DCamProf is using relative units, converting between QE and radiometric spectral response should be as easy as multiplying the QE with the wavelength.

I have seen both getting referred to as the spectral response of a sensor in documents, so I'm not sure which one is the correct one to be used with DCamProf.
This isn't specified anywhere in the documentation yet.