I asked @nate via e-mail a while ago if using gel filters or color correction filters to cancel the orange mask while DSLR scanning is a more effective way to get accurate color conversions within NLP. He said this was being explored and discussed on the NLP Facebook page. But since I’ve abandoned that cesspool of a social media site (no offense!) long ago, I was hoping we could revive it here and post results and findings that I’ve missed out on. I’m sure @Richard1Karash has chimed in on this one!
I have some questions to kick it off:
Wouldn’t color correcting the light source and neutralizing the orange mask condense the RGB channels in camera, thusly mitigating the risk of clipping on of the channels off to the left or right?
Does it interfere or throw off with the scanner simulation/film profiles built in to NLP?
I am also interested in this. I am using a Vivitar 285 flash into an enlarger diffusion box. I have tested the blue filter and it seems to Align the RGB channels better in the histogram. Is there any downside to this? I know NLP requires white balancing out the orange mask. Is there any reason that mask cannot be captured as a different color (neutral/bluish) the balances out?
In theory, yes, it could help. In practice though, the negative itself should very easily fit within the dynamic range of a digital camera sensor. The biggest biggest benefit would be in the blue channel, with the potential to capture more levels of informations (i.e. usable bit depth).
It’s possible it could throw it off slightly based on how the camera profiles are intended to work (extrapolating look up tables based on white balance setting). In my own tests, it didn’t make a significant difference one way of the other, which is why to date I haven’t recommended it. But happy to be shown otherwise! My hunch is that the spectral response of the light is more important than trying to balance everything in hardware (vs software).
There’s not really a downside if you like the results and have the gear already! I just don’t ‘officially’ recommend it because I haven’t been convinced that it is necessarily better and worth the time/cost/added-complexity.
I did a few tests with an old color enlarger in order to compensate for the orange mask. I also made a monochrome image using the color of the inverted mask and displayed it on an iPad. Both tests worked fine and the results were not worse than using white light. They were not better either…
I also tried overcast and blue skies as a backlight. It worked too…
NegativeLab Pro is fairly tolerant to exposure and lighting unless one or both of them are way off. Results can vary nevertheless. Which result is “the best” is either a matter of taste or the result of a painstaking series of tests that will probably still not deliver constant results because film types and development introduce a variability that asks for an “elastic” process rather than anything else.