Why is softproofing before print necessary - can't an optimal adaptation be computed automatically (at least a proposal)?

Question

I am struggling with the need of softproofing before printing photos. I usually use Adobe Lightroom for editing images and also for printing. I use color profiles - all good. What I do simply not understand is, why this softproofing is a manual process. As per my understanding, what Lightroom does when I activate the "Softproof" feature - it simulates on my monitor, how a print of the current image would look like on paper with the selected ICC profile. Then I have the opportunity, to manually adjust, until I get back to a look, that is similar to what I actually intended.

It is clear to me that for prints there are boundaries like limited dynamic range and color space. However, Lightroom should at least be able to easily provide a proposal of how to adjust contrast, exposure, tonal curve, saturation etc. to get close to what I originally wanted to have (simply my original edit).

My question is: If Lightroom can simulate the look on paper - why can't it simply automatically adjust the settings of the image in a way, such that it will look on paper, how I wanted it to look on the screen? Why do I need to do this manually (if obviously Lightroom "knows" the difference - and can display it to me!) ?

Answer 1

Because getting close to your original original edit is likely to require compromises, but there is probably any number of choices/compromises that can meet the technical requirement.

For instance, if you have an out of gamut color you could probably fix it with a reduction of saturation. Or you could probably fix it with a reduction of vibrance. Or maybe you could fix it with a reduction of contrast; or a lesser combination of all of them. The differences between the different methods may be relatively minor; but significant enough to someone who bothers with softproofing to not want them being made arbitrarily.

Otherwise you just let the printer manage the colors and it will print the image as best it can... just like getting quick prints made at a corner pharmacy store. The pictures probably won't come back that far from what you are expecting.

Answer 2

If you reduce dynamic range and colour gamut there is no straightforward way to adjust the image to look "correct".

When dynamic range is reduced there are three simple solutions:

1. scale the source material to reduce dynamic range and preserve all details
2. clamp the out-of-gamut values
3. tonemapping

(1) reduces contrast
(2) does not preserve all details
(3) reduces contrast

Similar argument applies to chromaticity and saturation range. Therefore, it is impossible for Lightroom make best decision automatically. There might be some good enough solution for some usescases though.

Answer 3

The basic answer is that your screen can display some colors that your printer can't. But your printer can also produce some colors that your screen can not. So there is no way to get your screen to show exactly what a print will look like.

Thus you must decide which compromises must be made.