Why does Lightroom Auto Tone sometimes make photos much too bright or dark?
Asked 4/21/2013
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2 answers
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Lightroom’s Auto Tone seems inconsistent for me. On some images it makes subtle improvements, but on others it pushes the photo much brighter or darker than I’d expect. In some cases it also seems to adjust several sliders at once rather than just making a simple exposure correction.
Why does Auto Tone behave this way, especially on very dark, very bright, or high-contrast images? Is this just a limitation of how Auto Tone analyzes the histogram, or is there some way to make it behave more predictably?
Originally by Photography Stack Exchange contributor. Source · Licensed CC BY-SA 4.0
Photography Stack Exchange contributor
13y ago
2 Answers
6
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.
Originally by user472. Source · Licensed CC BY-SA 4.0
user472
13y ago
0
Generated from our catalog & community — verify before relying on it.
Yes—this is a known limitation of automatic tonal correction, not just your taste.
Auto Tone analyzes the image histogram and tries to set black and white points from the darkest and brightest pixels, while also using highlight/shadow recovery. That means images with lots of dark content can get pushed brighter, and images dominated by bright areas can get pushed darker. A bright background or other extreme tones can strongly influence the result.
So the behavior can feel unpredictable because Auto Tone is not simply changing exposure; it may adjust multiple tonal controls to fit its idea of a balanced image.
In practice, Auto Tone tends to work better on moderate, evenly distributed scenes than on very high-key, low-key, or strongly backlit images. If you want consistent results, it’s usually better to treat Auto Tone as a starting point only, then fine-tune exposure, highlights, shadows, whites, and blacks yourself or build a preset around your preferred look.
An uncalibrated monitor can affect how pleasing the result looks, but it doesn’t explain Auto Tone’s basic behavior.
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