New to Ps & learning as I go. I import 2 images to Ps, one ambient lit shot & one over exposed & wish to highlight an area that is under exposed with my over exposed image making slight exposure adjustments. I select brush adjustments & choose a soft brush with 21% hardness, 100% opacity, 6% flow, if I paint over the area I wish to mask in will it only highlight to my selected setting 21% hardness, 100% opacity, 6% flow only or is it cumulative meaning the more I paint over the area the brighter it gets all the while keeping my finger on my mouse? If it does just paint in my selected settings if I release my mouse then click it again & start painting over what I just painted will it increase the brightness or stay the same?
If you want to build opacity with the layer mask, instead of using brush opacity and flow, use appropriate tones of grey. If you are looking for about half opacity, use 50% grey, for instance. That way you can use as many brush strokes as you like.
This assumes you are making local adjustments. If it was global, you'd adjust the mask density.
Thanks for the advise, I'll give it a try.