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RustyBug wrote:
+1 via increased contrast
If the shadows are too blocked up, then there is NOT enough contrast between values to be detected. By "opening up" the shadows, we are making the (shadow) values farther apart from each other (yet, closer to the whites on an absolute value) ... i.e. creating detectable difference (contrast).
Reducing the contrast is reducing the operand against the values (0-1)
If we have have values of:
.1, .2, .3, .4 and .5 and apply an (easy math) operand of ^2 (diff method's / diff operands), then the resultant is .01, .04, .09, .16, .25 for a total range of .24 variance.
If we reduce the operand back to ^1, we get our original values of .1 - .5 for a total range of .40 (i.e. more difference). Something in between, yields something in between.
Since we start off with values between 0-1, and our limits remain 0-1, the mathematical formulas operate on decimal values a bit differently than we tend to associate when we think of values on the 0-255 scale.
Adding contrast is in essence changing the operand value (the formula is a not quite this simplistic) that drives those numbers below .5 downward, and those numbers above .5 upward.
So, while the global application of the higher operand value will drive the sub .5 and the super .5 values farther apart like a wedge, the operand within the subset will drive those values closer together (thus lesser contrast allows them to remain farther apart to afford sufficient variance for detection).
I probably stated it awkwardly, but the math is applied to decimal values is why we can have less contrast = more detail ... where too much contrast can "cram" everything together so tightly you can no longer tell the difference, even if it is still driving your shadows farther from your lights.
HTH
P.S. Yeah, what Snapsy said (i.e. the midpoint fulcrum)
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So based on your explanation, isn't my OP premise correct regarding Feedback Terminology on the forums being confusing?....
when indicating more contrast is needed in a photo (improved perception needed) to improve some of the subtle detail is a localized "increase" of Contrast using a decreased global contrast value, to spread he localized values apart increasing contrast. (head spinning) Hence my original description of inconsistent or maybe better said, incomplete wording ie: missing the word Localized when saying increase contrast within the shadows. I understand his dispite spinning head and reassure my premise of somewhat confusing feedback terminology. YET all the while some feedback is spot on when you actually want darker darks for global contrast increase that sometimes produces localized contrast increase as well. Dohhh!
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