Probably simple!

[Kelvin Webb]

So, there are 2 computers where I am working, 1 has CC and 1 has CS4.

On one of them when you 'Apple M' for curves and press Auto you get a nice smooth S shaped curve which is a good starting point to then adjust the (normally) two points on the single curve line over the histogram - fine!

On the other one when you press Auto in curves instead of getting one singular smooth curve you get the three colour channels split and quite literally each colour line goes to the darkest and the lightest point on the histogram, there is no way to adjust these individual lines (and it looks 'not very good'!).

For the life of me I've looked at every setting in the Curves box that comes up but just can't see any difference. Where is it? What am I doing wrong?

Thanks for your help
KW

 

[IamSam]

Hello and welcome to PSG.

First, don't use 'Cmd + M' (Apple + M) to apply a curves adjustment, it can't be adjusted once applied.

Always use a "Curves adjustment layer" so it can be re-adjusted later. You can open a curves adjustment layer by going to LAYER > NEW ADJUSTMENT LAYER > CURVES..............or...............you can select it from the "half moon" icon located at the bottom of your layers panel.............or...............you can open your adjustments panel WINDOW > ADJUSTMENTS, then from this panel you can add a curves adjustment layer.

Question...........which Photoshop version does what with the Curves adjustment?

 

[IamSam]

When you use the AUTO function, the S curve is determined by the pixel content of the image, so it changes from image to image. Are you using the same image to test both Ps versions?

 

[Kelvin Webb]

CC is creating the smooth S curve
CS4 is splitting the colour channels

Not using the same images as they're tethered up to seperate cameras but both are shooting the same sort of stuff. I can try to take one image from one computer onto the other computer tomorrow but I'm pretty sure it going to do the same thing

 

[IamSam]

CC is creating the smooth S curve
CS4 is splitting the colour channels

Thanks

Not using the same images as they're tethered up to seperate cameras but both are shooting the same sort of stuff. I can try to take one image from one computer onto the other computer tomorrow but I'm pretty sure it going to do the same thing

You may be right. I don't have CS4 so I can't do a comparison. It may just be the different way the two versions treat the auto function, again, it's very hard for me to say without CS4. Also, I'm not accustomed to using the auto function of curves.

Because I've just tried it in a single Ps version, I do know that two similar images shot through the same camera under similar conditions produce two very different curves when using auto. I'm not at all surprised since manual adjustments (like I normally do) vary from image to image.

 

[Kelvin Webb]

Thanks

Because I've just tried it in a single Ps version, I do know that two similar images shot through the same camera under similar conditions produce two very different curves when using auto. I'm not at all surprised since manual adjustments (like I normally do) vary from image to image.

I'm pretty sure I would have been using it for years and never seen this happen before. Curves is after all one of the most used basic adjustments.

I will do a screengrab tomorrow of the curves window to show.