- Joined
- Jan 18, 2009
- Messages
- 2,587
- Location
- Fort Myers, FL
- Lightroom Experience
- Advanced
- Lightroom Version
- Classic
I'm digitizing lots of old negatives by photographing them. I like doing it with lightroom as the non-destructive nature is SO much smaller than the huge TIF's you get out of negative scanning (or conversely is more editable than the JPG's you might get).
In principle it is easy -- invert the RGB tone curve, then adjust the colors to take out the negative tint, and adjust the rest as desired (with some controls now working backwards or just different).
In practice the inter-relation of each change makes it hard.
It is easier in photoshop, since the curve inversion is destructive and once inverted you are just adjusting a positive (as opposed to lightroom where you are seeing a positive but adjusting a negative, e.g. moving toward yellow gives below, more exposure less, etc. )
There's tools like Vuescan which actually do this very nicely -- but again, the output is TIF or JPG.
So here is my question:
In terms of how ACR works, is there an optimal way to make adjustments. What do I tackle first, and with which slider.
Let's take the neutral, say I actually had a grey card in frame -- I can crop to just it and look at the histogram. I think I want the R, G and B to exactly overlap (though it's not clear where on the histogram I want it, left or right wise). But I can do that with temperature sliders (somewhat), with the tone curve itself (and there I can do it by either changing shape of a color or biasing the color while keeping it linear), or with the HSL sliders. Which is the place that, having adjusted, gives me the most "normal" adjustment for fine tuning later.
There's got to be, algorithmically, a "best" way to do this, that preserves the ... leverage?... of the other controls. E.g. do I set black first? And do I set it as white (pre-invert) or as black (post invert). And with which control? How do I remove bias in the tone curves -- keep it linear at a 45 degree angle and raise/lower both ends, change the angle, some sort of curve?
The more I do this the more I feel like I am just on the edge of finding a good approach, but not quite. Anyone have any suggestions?
In principle it is easy -- invert the RGB tone curve, then adjust the colors to take out the negative tint, and adjust the rest as desired (with some controls now working backwards or just different).
In practice the inter-relation of each change makes it hard.
It is easier in photoshop, since the curve inversion is destructive and once inverted you are just adjusting a positive (as opposed to lightroom where you are seeing a positive but adjusting a negative, e.g. moving toward yellow gives below, more exposure less, etc. )
There's tools like Vuescan which actually do this very nicely -- but again, the output is TIF or JPG.
So here is my question:
In terms of how ACR works, is there an optimal way to make adjustments. What do I tackle first, and with which slider.
Let's take the neutral, say I actually had a grey card in frame -- I can crop to just it and look at the histogram. I think I want the R, G and B to exactly overlap (though it's not clear where on the histogram I want it, left or right wise). But I can do that with temperature sliders (somewhat), with the tone curve itself (and there I can do it by either changing shape of a color or biasing the color while keeping it linear), or with the HSL sliders. Which is the place that, having adjusted, gives me the most "normal" adjustment for fine tuning later.
There's got to be, algorithmically, a "best" way to do this, that preserves the ... leverage?... of the other controls. E.g. do I set black first? And do I set it as white (pre-invert) or as black (post invert). And with which control? How do I remove bias in the tone curves -- keep it linear at a 45 degree angle and raise/lower both ends, change the angle, some sort of curve?
The more I do this the more I feel like I am just on the edge of finding a good approach, but not quite. Anyone have any suggestions?