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 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 ACR 8.3 /Lightroom 5 ? I guess my concern arises because the algorithm is moving the highlights into substantial clipping.
[also posted in the Lightroom forum]