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monks
10-18-2012, 11:53 AM
Hi, I was wondering is there any way to dynamically vary contrast with pen pressure in Photoshop? What I'm saying is, is it possible to apply contrast to an existing image via the brush in this way? I think that would be useful for working with heightmaps and greyscales in Photoshop. Perhaps, paint in greys on a layer with the blend mode set to a suitable mode might be one of doing it. Anyone ever tried something like this?

Thanks,
monks

torstan
10-18-2012, 12:36 PM
If you want to increase contrast in some areas then you can create a new adjustment layer -> brightness/contrast. Turn the contrast up, and fill the layer mask with full black. Then use a brush with opacity set to pressure sensitivity and colour set to white and paint on the layer mask. That should increase contrast in the areas that you paint with the degree of contrast corresponding to the pen pressure.

Is that what you're after, or something different?

monks
10-18-2012, 01:51 PM
I'll give that a go Torstan. Strangely, even though I use masks routinely in terrain software, I've never really used them in Photoshop.
There's so much in Photoshop that I've never used.

Just been fiddling with that for 30 minutes and I'm not getting anything.
Here's what I do: New adjustmentlayer > brightness/contrast
It does not give me the option of filling the mask with black, just white and various colours. so I choose white.
Then a dialog pops up so I set the contrast right up to about 80%.
Then I fill the layer with black and the mask goes black as it should.
Then I choose white paint and paint on the top mask layer and nothing.

Should I be creating a duplicate of the layer first?
Should I be selecting "use previous layer to create clipping mask" when creating the adjustment layer?

What's currently happening is if I keep the mask fill as white and paint with black, it lowers the contrast back to the original layer beneath
-that's what it should do, but if I fill the mask with black and then paint with white, I get no change when I paint so at the moment I can lower the reduce but not increase it.
I'm not sure about the brush opacity step you mentioned. I don't see any way of altering that in the Brushes Window.
I'm using CS2 here.

monks

torstan
10-18-2012, 02:32 PM
Can you throw a couple of screenshots up? I'll take a look.

Chashio
10-18-2012, 03:26 PM
Hey monks, I use CS4 so it may be different... but for me, the brush opacity setting is under Other Dynamics. Here's a screenshot.

49186

EDIT: Never actually read your original question... If you just want to work in greyscale and on height maps, then the dodge/burn tools on a low exposure setting might do very well for that. But I'd work on a duplicate layer just to be safe, and set the history undo to the newly duplicated layer so you can more easily revert if need be.

monks
10-18-2012, 04:56 PM
top shows the add adjustment layer dialog.
middle shows the effects of painting with black on white
bottom shows white on black

http://www.skindustry.net/medem/files/Temp/screens.jpg


No other dynamics in CS2 Chashio. Ok, I'll bear that in mind...I can use multiply masks in PS and whatnot but I'd quite like to be able to use
a brush with graphics tablet, and effectively be able to raise the terrain- like in a terrain editor. Terrain editors tend to be more taxing on
the system than PS- and I'm working on large files, so PS seems a good option.

monks