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lower cyan without increasing magenta?

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  #1  
Old 03-06-2017, 07:14 AM
anderson234 anderson234 is offline
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lower cyan without increasing magenta?

Hi,
I've learned several tutorials of Lee Varis. Regarding his method of adjusting/controlling skin color with CMYK values, I have a question: say with selective color tool, I first lower magenta in Reds, then lower cyan if nessisary, but that means increasing red, and as a matter of fact magenta will increase,too, thus spoiling my magenta control.
What should I do?
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Old 03-06-2017, 07:57 AM
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Tony W Tony W is offline
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Re: lower cyan without increasing magenta?

If this is purely for editing images within PS for colour correction I would suggest ignoring CMYK completely until such time as converting and presenting for press.

View this article by our own Andrew Rodney for a sensible approach
https://www.youtube.com/watch?v=dWaFDKrNrwc
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Old 03-06-2017, 08:32 AM
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Re: lower cyan without increasing magenta?

Ignore CMYK; it's an awful, output color space for this work! Stick with Lab (or RGB):
Here's a video on correcting skin tones without having to resort to CMYK:

Low Rez (YouTube)
http://www.youtube.com/watch?v=dWaFDKrNrwc

High Rez
http://digitaldog.net/files/SkinToneVideo.mov
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Old 03-06-2017, 10:40 AM
Sabrina81 Sabrina81 is offline
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Re: lower cyan without increasing magenta?

Quote:
Originally Posted by andrewrodney View Post
Ignore CMYK; it's an awful, output color space for this work!
With this technique, CMYK isn't used for output. Just to clarify.
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Old 03-06-2017, 10:55 AM
Sabrina81 Sabrina81 is offline
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Re: lower cyan without increasing magenta?

Quote:
Originally Posted by anderson234 View Post
Hi,
I've learned several tutorials of Lee Varis. Regarding his method of adjusting/controlling skin color with CMYK values, I have a question: say with selective color tool, I first lower magenta in Reds, then lower cyan if nessisary, but that means increasing red, and as a matter of fact magenta will increase,too, thus spoiling my magenta control.
What should I do?
When I lower magenta enough to reduce the red in skin tones, I then need to lower yellow to counteract the green that this introduces -- and maybe increase black a bit. Like this:
Attached Images
File Type: jpg redskin.jpg (99.4 KB, 23 views)
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Old 03-06-2017, 11:42 AM
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Tony W Tony W is offline
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Re: lower cyan without increasing magenta?

In these case the use of HueSat adjustments maybe a better choice than Selective Colour as you will reduce the red content (or indeed any other colour) without usually adversely affecting the others.

If you have a crossed curve type situation or wish to create one then Selective Colour may be a reasonable choice.

Example shown just altering the Red from HSB layer.
EDIT: Forgot this - you mentioned removing Cyan well this is -100 Cyan HSB layer. Not measured other values but Cyan gone without any observable effect on rest of image
Attached Images
File Type: jpg HueSatvSelective.jpg (195.4 KB, 11 views)
File Type: jpg HueSatvSelectiveMinusCyan.jpg (224.8 KB, 4 views)

Last edited by Tony W; 03-06-2017 at 11:57 AM.
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Old 03-06-2017, 01:57 PM
Shoku Shoku is offline
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Re: lower cyan without increasing magenta?

A magenta adjustment and then a red adjustment - I used your posted jpeg.
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File Type: jpg redskinMagenta and Red.jpg (502.2 KB, 14 views)
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Old 03-06-2017, 05:31 PM
anderson234 anderson234 is offline
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Re: lower cyan without increasing magenta?

Thanks guys, very helpful.

Quote:
Originally Posted by Sabrina81 View Post
When I lower magenta enough to reduce the red in skin tones, I then need to lower yellow to counteract the green that this introduces -- and maybe increase black a bit. Like this:
-magenta = +green
-yellow = +blue
+green + blue = +cyan = -red

I've seen this method before and thought about it, but can not figure out: why not simply reducing red ?
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Old 03-07-2017, 07:49 AM
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Re: lower cyan without increasing magenta?

Quote:
Originally Posted by andrewrodney View Post
Ignore CMYK; it's an awful, output color space for this work!
Aside from this work do you think CMYK can still have a point when retouching for pre-press because of the density concept and the "Maximum Dot" and "Minimum Dot" in print specification?

I believe it's useful to take total ink readings in the palette just to see how the image will print. It's just one value (Σ) to assess the image.

Quote:
Originally Posted by anderson234 View Post
I've seen this method before and thought about it, but can not figure out: why not simply reducing red ?
I am not familiar with the selective color adustment. Yet, why not just operating on the midtones slider?

Last edited by marameo; 03-07-2017 at 08:14 AM.
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Old 03-07-2017, 12:56 PM
Shoku Shoku is offline
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Re: lower cyan without increasing magenta?

Quote:
Originally Posted by marameo View Post
Aside from this work do you think CMYK can still have a point when retouching for pre-press because of the density concept and the "Maximum Dot" and "Minimum Dot" in print specification?
Yes. We've been retouching in CMYK for more than two decades. We also use RGB and LAB as needed. CMYK is very intuitive and has some benefits the other color spaces don't. Our output is for press, so we would naturally convert to our output CMYK anyway. Using it for editing has never slowed us down or made the process more difficult, in some cases it makes things easier.
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