I like this. Very useful tip. Thanks a lot

One more … when using the adjustment brush tool, the Option/Alt key temporarily switches to erase – very handy when you colour outside the lines 🙂

1-Main Panel:
All the sliders that deal with exposure show you if you are blowing highlights or shadows.
Whites / Highlights: Shows the screen in black, and shows in colors when it blows them
Blacks / Shadows: Shows the screen in white and shows in colors when it blows them
Exposure: This is the strangest one. IT should show to the left or to the right (blowing blacks or blowing whites) but it only does it to the highlights/ whites.

2-Split toning:
Only balance does something with ALT. I dont know exactly what it is. I think it is exaggerating the effect, but it even does something when you set everything to zero, so it is a bit strange. Would be cool to know exactly what it really does.

3-Detail:
Almost everything in detail does something when pressing ALT:
Sharpening – Amount: Puts the screen in black and white to be easier to see the effect of the sharpening.
Sharpening – Radius: Goes to black and white, but concentrates on the borders.
Sharpening – Detail: Same as before, only concentrates on the borders.
Sharpening – Masking: Also in black and white, does a kind of auto mask of the zones that applied (I suppose this is done with contrast detection, again would be good to know exactly how these work.)
Noise reduction – Luminance: The same as sharpening. Goes to black and white to see it better.
Noise reduction – Detail: Same as before, only black and white.
Noise reduction – Contrast: Same as before, only black and white.

4-Lens correction:
There are some in color (just play with them) to see where it is affecting it)

Now, if you have some way to reach adobe, or if they are reading. Some ideas:

1-Vignette: Pressing alt could make it more obvious where it is applying, so when you are subtle, you can check where it is. I know, you can crank it up, and check it (That is what I do) and then lower it back again, but the same could be said of many of the uses of alt.

2-Grain: Could go to black and white to see it better.

3-On curves, also, some way to check where it is blowing highlights or shadows. Yes, again we have the triangles on the histogram, but the same can be said of the highlights and shadows sliders.

4-Clarity / vibrance / Saturation: I don’t know, maybe show where it is applying the vibrance, or the clarity.

5-Black and white sliders. Maybe, when you press on red, for instance, everything in red could go black and all that has red could go white, so it is obvious where you are applying the changes and if some place has red that you didn’t know will be more obvious too. Maybe this could be done also for the rest of the HSL sliders.

Just some ideas Adobe!!!!

Yes….for once I knew all of these tips, but I check here all of the time because there is always something to learn. Thanks RC keep them coming.