Selective Color Slider Meaning

GA
Posted By
George_Austin
Oct 29, 2003
Views
504
Replies
6
Status
Closed
In PS7 Selective Color (Relative or Absolute) the slider percentages do not correspond to any rational assumed or intuitive meaning. They are percentages of what?

Donnie O’Quinn’s PS Shop Manual comes closest to defining them. but his definitions don’t hold up.

PS has scores of similar dialog boxes and each one seems to be a special case. For just one other example (which I did decipher) try understanding the saturation slider in Hue/Saturation Colorize.

In general. there is no consistent interpretation of PS dialog box slider numbers and few explanations are given. Figuring each one out is excrutiatingly tedious—why aren’t suitable definitions in Help?
Related Tags
color selective slide

How to Master Sharpening in Photoshop

Give your photos a professional finish with sharpening in Photoshop. Learn to enhance details, create contrast, and prepare your images for print, web, and social media.

CC
Chris_Cox
Oct 29, 2003
In relative, they are percentages of the existing color. (increase or decrease by percent)

In absolute, they are absolute percentages (of the primaries) added or subtracted to the current color.
GA
George_Austin
Oct 30, 2003
Chris

Start with a 40/50/60/0 CMYK swatch

In Selective Color, set color = reds, method = absolute

Set the cyan slider to +10,+20,+30,+40,+50,+60,+70,+80,+90,+100

Cyan in the patch becomes 41,42,43,44,45,46,46,46,46,46

The cyan increments are not percentages of the existing cyan

The slider values appear to be absolute cyan increments in TENTHS

The action stops when the slider reaches 60

None of this behavior seems to agree with your definition

This is just one example—other examples with different behavior abound. I don’t think we’ve got this baby nailed down yet.
CC
Chris_Cox
Oct 30, 2003
No, in ABSOLUTE mode they are adding or subtracting ABSOLUTE percentages.

In RELATIVE mode, then it’s making RELATIVE adjustments.

But it also applies ONLY to the color range you’ve selected (in this case reds) and fades as it goes from one color range into another.
GA
George_Austin
Oct 30, 2003
Chris,

Can you reconcile the numbers in my sample case to your statement "…they are adding ABSOLUTE percentages…"?

1 and 2 and 3…added to 40 corresponding to slider settings of +10, and +20, and +30 are absolute percentages of what?
CC
Chris_Cox
Oct 30, 2003
Start with a 40/50/60/0 CMYK swatch

In Selective Color, set color = reds

Is 40/50/60/0 a red color? No, it’s a dull brown (hue is closer to orange, almost halfway between red and yellow).

If it’s not red, then it is not going to get the full effect of adjustments applied to reds.
GA
George_Austin
Oct 30, 2003
Is 40/50/60/0 a red color?

At a hue of 29, it is more red than it is yellow, cyan, or magenta or green or blue. It is in the "reds range".

How is the hue quantitatively handled in determining what fraction of "the full effect" you get? There is much more to the formulation than revealed so far.

How to Improve Photoshop Performance

Learn how to optimize Photoshop for maximum speed, troubleshoot common issues, and keep your projects organized so that you can work faster than ever before!

Related Discussion Topics

Nice and short text about related topics in discussion sections