Is Lightroom Auto Tone very dodgy?

Question

I don't know if it is just my taste, or is lightroom's auto levels like rolling a dice? Sometimes is makes subtle adjustments that do improve the visibility of highs and lows, but 50% of the time is turns the images extremely bright or dark.

It could be my screen - it is not calibrated - or my personal taste that differs from the core customers of Adobe. Is anyone else experiencing this? Is there a very to teach it how I like the balance? In machine vision cameras there's a setting to adjust what level should be mean for its auto exposure.

Another issue I find is that it adjusts too many parameters, which could explain the dodgy performance - it would be better if it only adjusted "exposure" and "brightness", to bring the histogram within reasonably bounds, from which the user can then tweak shadows, and highs (or save that in a preset).

I wish I could use auto exposure in my default preset, but its dodgy performance makes that impossible and I have to adjust exposure for all images individually.

Here are examples where it makes it very over exposed, or makes a dark image even darker:

And a more normal situation:

Answer 1

Auto tone works by matching the lightest and darkest pixels in each channel to the pure white and pure black points in the image and clips at both ends of the histogram. However, in Lightroom, it also tries to take advantage of adaptive highlights and shadows.

The first image will be heavy to the dark end of the histogram and if that end is clipped, it's going to lighten the overall image, as it did.

The second image will have a strong light end of the histogram and if that is clipped, will tend to darken, as it did.

The third isn't quite as extreme, but since LR works "top down" trying to take advantage of the highlights, so I think it's being heavily influenced by the white background.

A quick Google on LR auto tone seems to indicate that a lot of people don't find that it does a good job, that PS is better at it by not trying to take advantage of adaptive highlights and shadows. I suspect that the first two images would be a severe challenge, in any event, to any form of auto adjustment. They're very heavily dominated by one colour channel.

Answer 2

No the Lightroom has different behaviour at any installation. I have installed at 4 pc's in my office. The same version, same photo and none of them has the same exposure in "auto tune" Even when i install a different version at the same pc, the same photo has different exposure and brightness.