Help with weird behavior of photoshop curves tool

[DanK]

I just noticed something very odd when I dropped Trevor's image of Mt. Unwin (Mount Unwin in Jasper National Park) into Photoshop. The curves tool inverted.

All of the histograms change and then show a symbol that let's you redraw it with uncached data. All of these are uncached.

Here is the simple histogram. It looks just as Trevor's image suggests it should. It looked to me as though he could move the black point up a tad, and that is what this shows.



Now, here is the histogram from the levels tool. Basically the same.



Now, the clincher: here is the curves tool.



You'll see that it is reversed right to left. And as that suggests, if you pull up on the middle, it DARKENS the issue.

I thought maybe there was some weird setting in Photoshop--I just installed it on a new computer--but when I tried this with Brian's beanstalk image (which is not B&W), the curves tool worked as it should.

When I loaded Trevor's image, Photoshop said that the ICC profile is invalid and would be ignored. Perhaps that's a clue.

anyone know what is going on with this?

Thanks

[Manfred M]

I suspect that you have Curves set up the way that people preparing images for CMYK / Offset Press workflow use curves.

Open up the curves dialog box and make sure that you have checked the appropriate box; highlighted in red in the image below.

For the Curves Adjustment Layer, you get to the dialog from the menu flyout. The way I have set up the options will give you
curves operating the way you are used to.

[DanK]

Manfred,

Thanks very much. That was it. For some reason, that's how Photoshop installed itself on this computer. It didn't on my earlier computers.

Dan

[Manfred M]

I’ve run into a few photographers who prefer that “backward” setup, but they are former commercial photographers who worked in the print industry for many years.