CS4 Curves Issue

[Ptax]

Recently the "Curves" adjustment on CS4 has stopped working on certain photography. When I click on "Curves" for a photograph it does not allow the "AUTO" option. Thoughts?

[Photo-John]

I hope you don't mind but I moved your thread to our software and post-processing forum where it's a better fit.

I rarely use curves in Photoshop and I've never had what you're describing happen to me. But just to be clear, do you have curves saved with layered files and that's where they've quit working? Or you can't apply a new curve on some files? Are these old files or are there new files that it doesn't work on as well? I'm asking these questions to see if we can determine whether it's a problem with the files or a problem with Photoshop. I have had certain tools just quit working correcting in Photoshop. If that happens I assume something has been corrupted and it's best to re-install the software, But if that's not the case then it's probably a file compatibility issue that you just haven't identified yet.

[Ptax]

It has started happening on photographs I have edited for the first time and on the original picture. I can't apply curves to just some files.

Thanks for moving my thread. I appreciate it.

[mjs1973]

Is there anything special about these files? For example, some tools wont work on 32 bit files, or even 16 bit files. What types of files are you working on, jpeg, tiff, psd?

[Ptax]

jpg shooting with a Pentax Kr

[mattgenton]

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- matt

[Anbesol]

have you tried both methods, Ctrl+M to manage curves on the original document, and the curves layer adjustment option, which applies the adjustments to a seperate layer? Curves layer adjustment is preferable as it doesn't adjust the original file, only applying its effect as an overlaid layer. On the second window down there should be a tab called "adjustments", hit the button that looks like a tonal curves graph and you get the option to adjust. When completed with the image you can press ctrl+shift+e to merge the layers and make a flat document (if you so please), or resave as a PSD for a lossless save.

Auto curves is kind of useless, sometimes it works, sometimes not. In my experience with portraiture, its more miss than hit, flesh tones are a picky hue. If you simply understand how the curves line works then manipulating it yourself can be more effective. Moreso because, all automatic curves does is raise the black points and lower the white points, if anything. Whereas, if you do it yourself, you can bend the curve to your liking, in each individual color channel as well with much more acute, fine tunes control.

The color balancing effect of auto-curves is simply made by the adjustments in white and black point in each channel, red green and blue. Its very easy to learn how to do it better than auto-curves.

Also - shooting in jpeg kills your tonal width, very dark and bright tones get blown and you end up adjusting for color temperature in curves, when you should be doing it in kelvin and tint on the raw converter.