Given all the recent interest and work on the film simulations thread and all the discussion around digital development etc… I just thought I would share this little snippet that I stumbled across in case it might be if any interest to any one
really nice writeup and interesting DIY project. and yes, spectral processing is completely different and you can’t achieve it by messing with rgb (wb multipliers or matrices). also good to read that everybody has issues with getting white balance right with these scans .
i think the technically more correct way of inverting the scan + open source software we have (provided by @arctic).
fair point that the sensitivities of digital cameras have more spectral crosstalk than sensitivities of paper. i mean we are using spectral upsampling and will use paper sensitivities in the inversion process, but of course this will come out slightly different to scanning with more narrow band lights in the first place.
since this is about digital cameras/the scanning step i don’t think it makes sense to try these lights in the film simulation code as printing/enlarger light sources (where the paper sensitivities will select what they need anyways). there is something about overlap between dye densities and paper sensitivities and the light source filters which has quite an impact on colour balance… but i suppose is a different issue.