Thanks for the lines of code. It confirmed that I’m at a good spot with exposure.
I also found out that slightly “overexposing” doesn’t pronounce the HQ cameras noise as much while the highlights can be entirely recovered.
I’m in fact rather in the “grain is the picture” camp, which makes the camera’s sensor noise all the more annoying. I can pretty much reveal it in any frame when I increase expousre and look at the film borders.
However, it gets much harsher if the image was slightly underexposed (or, if I go by sprocket hole brightness, correctly exposed):
As long as the scene itself isn’t too dark, I think it won’t be an issue. But if it’s a really dark scene like this sunset:
It gets kind of bothersome, because you can see it even if you dial exposure down to the initial values. Each frame has a different pattern and it keeps jumping around.
My suspicion is that it is caused by the rather large gain multiplier of the red and blue color channels, compared to the green channel.
Has anyone tried using a warmer lamp, so that both channels roughly have the same gain? Or would that negatively affect the representation of the film’s original colors?
I vaguely remember a technique from astrophotography, in which you take one or more long-exposure images with the lens cap on, so you receive a noise profile that you can then somehow subtract from the actual image. Maybe there’s a way to create a kind of “noise stack” to oppose the Pi HQ camera’s sensor noise…? I’d need to re-check how that’s done exactly…