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Author Topic: Lightroom Auto [Tone] – Bizarre Behaviour  (Read 1926 times)
Simon J.A. Simpson
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« on: April 14, 2014, 01:10:45 PM »
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As only a fairly recent convert to Photoshop CC and Lightroom 5 (from Bridge and Photoshop 5.1) I have only just observed tis bizarre behaviour.

I first noticed this in Lightroom (5.3) but have confirmed the same behaviour in ACR 8.3 for Bridge CC and Photoshop CC, which I understand share the same ACR technology (?).  Whatever – the results are the same.

Sometimes I find it is useful to take a look at what the “Auto [Tone]” button in ACR and now Lightroom will produce in terms of the tonal balance of an image.  Using this with Lightroom 5.3 (and ACR 8.3) produces a substantial lightening of the image and an increase in contrast which to, my eyes, is unpleasant.  This would be, perhaps, a matter of taste, but on a recent image it actually moved the highlights into clipping; and not just by a little but by a lot.  Surely this can’t be right ?

Observing what the algorithm does to the sliders, it lightens the highlights and darkens the blacks considerably (by 35–45%), and increases the exposure and slightly decreases the contrast.

Going back to ACR 6.7 (my last version which sometimes produced helpful results) I note that the algorithm darkens the same image slightly retrieving any blown highlights producing, overall, a relatively good tonal balance (if a little dark).

I have now replicated the above on other images, so it is not just the product of one image.

So, my question is this:
Is this some setting that I’ve inadvertently changed and need to restore ?  Or this this the ‘normal’ behaviour of Lightroom 5 / ACR 8.3 ?  I guess my concern arises because the algorithm is moving the highlights into substantial clipping.

[also posted in the Camera Raw forum]
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Simon J.A. Simpson
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« Reply #1 on: April 14, 2014, 01:26:16 PM »
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Just discovered that this seems to be a difference between the Adobe Camera Calibration Profiles “2010” [ACR 6.7] and “2012 (current)” [Lightroom 5.x and ACR 8.x].

Oops, did something go wrong in the “calibration” ?  Wink
« Last Edit: April 14, 2014, 01:30:20 PM by Simon J.A. Simpson » Logged
Simon Garrett
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« Reply #2 on: April 14, 2014, 03:52:29 PM »
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I don't know why it is, but I've certainly found that auto-tone can sometimes increase whites way into clipping. 

Clearly there are times when it's OK to clip highlights - when the highlights are specular highlights for example.  What I thought it was trying to do with auto-tone was to adjust white and blacks to the highest and lowest levels of "useful" pixels.  In other words, ignoring specular highlights, lights or the sun in the frame and so on, and similarly ignoring blacks that are obviously way beyond having any useful information.  However, LR/ACR auto-tone seems to overdo it on the whites at times.  This is with Nikon D300 and D800; I can't speak about other cameras. 

I often use auto-tone to see what it does - frequently then un-doing it if I don't like the look of it.  Even where I do use auto-tone as the basis for further adjustment, I find myself winding back the whites sometimes. 
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Tony Jay
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« Reply #3 on: April 14, 2014, 06:50:01 PM »
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Simon, I would not stress about this.
Think of auto tone as a 'democratic' tool that is designed to do the most good for the most pixels.
I have certainly noticed what you have observed but it honestly does not matter.
If you do use auto tone as a basis for editing it is just that - a start, and not the end.
Edit to your heart's content.

Tony Jay
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Simon Garrett
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« Reply #4 on: April 15, 2014, 02:35:17 AM »
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Simon, I would not stress about this.
Think of auto tone as a 'democratic' tool that is designed to do the most good for the most pixels.
I have certainly noticed what you have observed but it honestly does not matter.
If you do use auto tone as a basis for editing it is just that - a start, and not the end.
Edit to your heart's content.

Tony Jay

No I wasn't stressing - I do exactly what you say. 
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Simon J.A. Simpson
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« Reply #5 on: April 15, 2014, 05:24:40 AM »
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The other Simon isn't stressing either.

Grin

I follow much the same procedure as Simon Garrett.  I was just surprised to find what now appears to be the ‘2012 camera calibration’ adjusting images into clipping, by a lot.  These weren't specular highlights either, but obviously the algorithm thought so.

Ho hum.
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Tony Jay
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« Reply #6 on: April 15, 2014, 05:31:20 AM »
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Good to know no-one is stressing!
My post was directed to the OP though.

Tony Jay
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elied
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« Reply #7 on: April 15, 2014, 06:52:43 AM »
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It is hardly surprising that the Auto Tone works differently in PV 2010 and PV 2012; the methods of handling tonality are so different that the Auto algorithms are working through very different curves and PV 2012 also has the factor of the auto-adaptive changes in the curves.

When working a large number of images quickly I use Auto Tone because it generally gets Exposure and Contrast pretty close. I then reset Highlights and Shadows as needed and finish with new Auto settings for Whites and Blacks (sort of Auto Levels) by doing Shift+double-click on each one.
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stamper
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« Reply #8 on: April 15, 2014, 06:55:08 AM »
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Michael, the owner of the site, said in one of his videos that he has never been tempted to even press the auto tone button! The image that you see, before you have even processed anything, has been "auto toned" already. It has contrast and exposure added as a default therefore you are "auto toning" twice. Best to follow Michael's advice imo.
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Simon J.A. Simpson
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« Reply #9 on: April 15, 2014, 08:21:11 AM »
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Seems Michael's advice is good.  Point taken.
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Simon Garrett
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« Reply #10 on: April 15, 2014, 08:26:53 AM »
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Michael, the owner of the site, said in one of his videos that he has never been tempted to even press the auto tone button! The image that you see, before you have even processed anything, has been "auto toned" already. It has contrast and exposure added as a default therefore you are "auto toning" twice. Best to follow Michael's advice imo.

That's not quite my understanding. 

Since around LR3 or 4, the LR/ACR profiles are slightly image-adaptive (especially in terms of highlight protection) but not much, I believe.  The auto-tone button does much more to:
  • estimate where the mid tones should be, and centre them in the histogram (with "Exposure")
  • adjust contrast to provide a reasonable spread of mid-tone
  • adjust black and white to expand what it thinks is the meaningful information to fill the histogram
  • adjust highlights and shadows to spread the information in the uppper and lower parts of the histogram
I'm not sure it does it in that order, but I'm sure it's much more image-adaptive than the code of the basic raw conversion. 

ACR/LR has no idea of the photographer's intent in the image, so auto-tone often gets it "wrong".  As it often spreads the histogram, I find it useful to try it, to see if I'm missing some useful correction to the image.  However, as often as not I then undo, and start again from scratch. 

I might be completely wrong about all this, and stand to be corrected by anyone more knowledgeable about the adatpive aspects of Adobe raw conversion, but I don't think auto-tone is doing the same thing as is done in the basic raw conversion.  If it did, you would expect it to have a null effect, as the work has been done already.  And why would Adobe provide the function in that case?
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stamper
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« Reply #11 on: April 15, 2014, 09:50:49 AM »
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Quote

And why would Adobe provide the function in that case?

Unquote

For someone who wants a quick "fix"? Some photographers like to batch process a lot of images with the same settings regardless of the fact that every image is different with regards to exposure. If someone has gone to the bother of nailing exposure in camera then why "ruin" it by using auto tone? Surely the photographer should, with respect to his image, do the thinking as to how the finished image should look rather than auto tone? Roll Eyes
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Simon Garrett
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« Reply #12 on: April 15, 2014, 10:04:40 AM »
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Quote

And why would Adobe provide the function in that case?

Unquote

Sorry, perhaps I didn't make my point clearly.  The suggestion raised earlier was that Adobe's raw conversion already applies adaptive processing - a sort of auto-tone - and so applying auto-tone is doing it again.  My point was that in that case (Adobe does auto-tone anyway in raw conversion) then a user applying auto-tone wouldn't do the same only more so, it would do nothing; it's already been done.  My question applied to that: why would Adobe provide an auto-tone function if they already do auto-tone in the basic raw conversion?  (Hint: that was a rhetorical question.  I don't think they would!)

  
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Slobodan Blagojevic
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« Reply #13 on: April 15, 2014, 10:20:54 AM »
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That's not quite my understanding....

+1

If you under/over expose your shot, Adobe is not going to normalize that "by default."

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