Saturation slider doesn't affect some colors

[whitestone]

A scanned image (from slide, 16 bit) was somewhat dull, so I added a

Hue/Saturation adjustment layer. When I adjust the saturation slider, I get

immediate posterization due to the fact that some colors increase in

saturation, while others ((156, 132, 0) for example) are immune to the

saturation slider and never change. Any suggestions on what I can do to get at

least a little boost in saturation without the posterization?

[wnw]

Rob, are you adjusting the saturation globally (across all the colours) or individually?

[thomas_sullivan]

well, concerning your example of 156,132,0......the big problem with that color is the 0 setting for blue. You can't saturate pure black.....there's nothing to saturate. so, it will be one of the least adjustable colors that can be saturated.

 

Neil's implication of using seprate saturation for the different colors will keep the posterization down in the easily saturated colors, and help beef up the others.

 

Also, I have noticed that if you shoot in RAW........I shoot in RAW and JPEG, so I see difference in adjusting dif things between the two......you can saturate more intensely before the posterization starts......not a lot, mind you, just enough sometimes. Then finish up in TIFF in photoshop proper.

 

You can also sort of "fake" saturation a little by using the lightness slider for the dif colors. It really ain't saturating it, but the end result, done carefully and gingerly, is the same look in the end.

[fred_bonnett2]

Try doing hue/saturation without an adjustment layer (image>adjustment>hue/saturation). You may have had some sort of selection when you created the layer.

[whitestone]

Neil, I was adjusting the saturation globally.

 

Thomas, it just seems a little odd to me that the '0' in blue prevents the red and green from adjusting. (Hmmm, when I get home, I'll try mixing in a (0,0,1) layer (to get the blue off 0) and see if that will allow saturation without posterization.)

 

Fred, there were no selections. (It would have to be quite an involved selection to posterize along the colors the way it does.)

[terry_spade]

Have you tried levels or curves?

[wnw]

Curves is a neat way to adjust color. You have to work in either R(ed) G(reen) or B(lue). Dragging the curve down adjusts for the 'opposite' color e.g. Blue curved down produces yellow and so on.

 

You can play (study) with opposite colors at http://www.colortools.net/color_complementary.html

 

There is a neat diagram somewhere that I just can't find that shows which colors are opposite each other. It's invaluable for learning color correction. (I just found a simple one at http://www.hypermaths.org/quadibloc/other/colint.htm)

 

The other method is to create a Channels adjustment layer and play with the RGB there.

 

In any event, you really shouldn't adjust colors globally but rather individually. The difference is pretty great.

 

To boost colors you can try 'Local Contrast Enhancement' - an easy but very effective method for bringing dull photos to life. You can read up at http://www.cambridgeincolour.com/tutorials/local-contrast-enhancement.htm although some other good articles exist on ther web.

 

Good luck.