I’ve just been having a play around in PL3. It struck me that i never use positive Blacks values in the selective tone tool. It got me wondering whether i should be, and when to. I’ve always just used positive Shadows if the low tones needed a boost (after setting exposure).
Thanks.
Yes. I find raising shadows often brightens too much of the image, including some midtones. Raising blacks is good for when the darkest areas are crushed and I don’t want to lose too much contrast while recovering those shadow details. Or when there’s too much shadow contrast but middle and light tones are fine.
I use these sliders as @Egregius does and I often use the tone curve instead of smart lighting.
I’ve the same approach 
Thanks for the reply. Yes, that’s kind of what i was wondering too. In my experiments i found the Shadows slider (when used positively) tends to keep the crushed parts seated and tends to lift the more brighter shadows the most, and obviously only effects tones in the shadows range (as far up as the beginnings of the mid tones). Using too much Shadows tends to throw the contrast out. However, i found that positive Blacks has a more linear effect across all the tones and is useful for shifting the whole histogram to the right & so lifting the dark clipping area back in detail.
So assuming i’m right, i’d use positive shadows if there is little to no dark clippping to begin with, or i’d use positive Blacks if the image has dark clipping to begin with (crushed tones?)
Would that be right?
Interesting. Can highlights be recovered using the tone curve? If so how?
Click on the top right point “highlight” and use the arrow keys to bring it down like 3-5 times to just drop whites a tide so it be like “250 instead of 255”, you can always do the same with bottom left “shadows” by using arrow keys to bring it up 3 to 5 time just to raise the black a tide above “0”
Brighten the image slide the top right point left to increase “brightness”, or slide bottom point “shadow” right to increase shadow.
Maybe @Pieloe should add a crash course for curve on his tutorial page, even though you’ll find many online.
*numbers above are to taste, sometime you’ll need to adjust depending on the image you’re working on.
*this is on Master not red or blue or green channel which will all give different results.
This post being about the black slider, my mention of the tone curve is pointed at darker areas of the image.
Regarding highlights: PhotoLab often shows highlight warnings because the selected preset causes highlights to get too bright, even if data in the raw file is perfectly within bounds as shown in Raw Digger. Bringing down exposure und bulging up the tone curve can fix this.
Highlights that are really blown cannot be recovered but replaced by something that more or less fits…
By what ? Could you elaborate or give an example.
I use the boxes function of Smart Lighting for this problem. set two or more boxes on your image:
1 highest/brightest spot.
2 darkest place/spot
3 on the points of your interest like a person or a object to nail that exposure on that object.
(mostly only 25%) and use the auto average weight of exposure to lift/lower the “middleground”.
And then start with selective tone and contrast sliders and or masks and controlpoints. positive or negative to adjust on local level
Works every time.
Imagine a nightscape with a completely blown moon
Nr 1 is easy if you have Photoshop. We can call this “fixing” an image, we might call it “cheating” too. Depends on whether you try to sell the result as art or fact. Basically, all you do to your images will be submitted to this question (art or fact?)
Now, if our “moon” is significant, we’ll have to admit that we missed exposure. If contrast s simply too high for a non-biologic sensory system, we’d have to use HDR techniques in order to overcome the limits.
Thank you. But I thought of something inside PhotoLab. Photoshop does not interest me and I have neither PS nor LR.
And yes, I use positive (as well as negative) blacks in selective tone. Not always of course and generally with values between -15 and +15…