Top! My main problem with luminosity masks was/is loosing contrast. Figured some of this out already but still there are cases where I struggle with keeping contrast. The Math is very interesting to know. But I kept asking myself: why did Adobe design it this way. What is/was the reason. Seems counterintuitive. Not sure if you know, but would be interesting.
Really useful - your panel is great - just wondering about the 1st image - what would be the difference between using a subtracted selection and using blend-if to restrict the adjustment from the blacks?
Hi Greg, Thanks for great the lesson. I have a question regarding to the formula. I understand that you try to remove the pure black from the mask by subtracting d5 from the d3. But according to the formula, d5 (shadow of the rock) has the value very close to pure black let say d5 is 10% and the d3 (the majority of rock) is 35%. The deduction of value from the subtraction seems very minimal. 35%-10%*35% > 35%-3.5%=31.5% So the subtraction to maintain the contrast would not be very obvious? Or photoshop is just taking the black selection (d5) away from the white mask (d3) without doing any calculation? thanks a lot
The subtraction is just changing the targeting (no longer affects black). This prevents you from making an unwanted change (lightening pixels which should stay black). It doesn’t care about the image as a whole, it is evaluated at the pixel level.
Same problem but worse, black would be most selected, and therefore contrast would be extremely flat. Need to prevent blacks from being lightened, which requires subtracting it out.
@@gregbenzphotography That makes sense, thanks. It would also be interesting to see how you created those saved masks that you had for the sky, and left and right stack
@@gregbenzphotography Did you generate that from a lights mask, then refine it with the quick select?... The reason I ask is because the edging is perfect and sometimes the quick select isn't good around the edges
The saved channel here no, but typically I would do something like that for best quality. Or I would either feather it or intersect it with luminosity to improve the edge as needed.
My brain just exploded. I'm going to have to watch this several more times!
Same here even more since it's not my native language and Greg talks that fast..
Much better than dodging and burning every little crevice.
1000%
Greg, a very useful video tutorial and the write up below really helps too. Thanks!
Wow - eye-opening stuff! Thanks for your (as ever) perfectly crafted explanations GB, and for the write-up as well (
Thank you!
Amazing thank you Greg 🙏
Top! My main problem with luminosity masks was/is loosing contrast. Figured some of this out already but still there are cases where I struggle with keeping contrast.
The Math is very interesting to know. But I kept asking myself: why did Adobe design it this way. What is/was the reason. Seems counterintuitive. Not sure if you know, but would be interesting.
Really useful - your panel is great - just wondering about the 1st image - what would be the difference between using a subtracted selection and using blend-if to restrict the adjustment from the blacks?
Much more control.
Hi Greg, Thanks for great the lesson. I have a question regarding to the formula. I understand that you try to remove the pure black from the mask by subtracting d5 from the d3. But according to the formula, d5 (shadow of the rock) has the value very close to pure black let say d5 is 10% and the d3 (the majority of rock) is 35%. The deduction of value from the subtraction seems very minimal. 35%-10%*35% > 35%-3.5%=31.5% So the subtraction to maintain the contrast would not be very obvious? Or photoshop is just taking the black selection (d5) away from the white mask (d3) without doing any calculation? thanks a lot
The subtraction is just changing the targeting (no longer affects black). This prevents you from making an unwanted change (lightening pixels which should stay black).
It doesn’t care about the image as a whole, it is evaluated at the pixel level.
@@gregbenzphotography thank you!
Greg - just for reference: please drop us an link to tutorial where you describe 'selection options' window?
Click “?” and then “Sel” in Lumenzia
Why not just start with a D5?…It would’ve helped to see what the mask looked like when you subtracted it
Same problem but worse, black would be most selected, and therefore contrast would be extremely flat. Need to prevent blacks from being lightened, which requires subtracting it out.
@@gregbenzphotography That makes sense, thanks. It would also be interesting to see how you created those saved masks that you had for the sky, and left and right stack
That was via the quick select tool
@@gregbenzphotography Did you generate that from a lights mask, then refine it with the quick select?... The reason I ask is because the edging is perfect and sometimes the quick select isn't good around the edges
The saved channel here no, but typically I would do something like that for best quality. Or I would either feather it or intersect it with luminosity to improve the edge as needed.