Question about ACR sliders: What exactly do they do?

Question

Hello forum, my first post here. I have been using PS off and on for many years for very basic things, cropping, color adjustments, cloning with layers, ect. While I tend to dislike adjusting my tones too much, I have grown interested in knowing exactly how the sliders affect the image. I understand EXPOSURE essentially raises the exposure of everything, and I heard HIGHLIGHTS and SHADOWS affect only the extremes of either end. But is the above true, and, what do BLACKS and WHITES do? FYI I have CC and am up to date. Just wondering if anybody can offer some technical explanation to the sliders. Thanks in advance!

Answer 1

Hi Amanda.  Best advice I can give is to closely watch the Histogram as you adjust the sliders.
Black is where all three channels have a value of zero, and white is were all three channels have a value of 255
Shadows will affect tonal values between zero, and something like 50,50,50
Highlights will affect values between something like 200,200,200 and 255,255,255
Note I am gestimating those figures.
Contrast will reinforce the shadow end making shadows darker, and do the reverse at the highlight end.  If you understand Curves. it is like add an S shaped curve to am image.
Clarity works similar to Contrast, but whereas Contrast will block up the blacks pushing low tonal values further towards full black, and do the opposite at the other end of the histogram,  Clarity reinforces the low tonal values without moving them towards full black, and the revers for highlights.  Clarity is one best seen visually by watching the histogram.