Computer Graphics with Photoshop - Question: replacing color range

Author

Question: replacing color range

2005-10-24, 10:15 pm

Hey, all.

I recently did a photo shoot, in which we used some colored gels for
highlights, and a lot of backlighting (for increased contrast and
shadow). The gels were not my idea. ;-)

Some of the shots that I thought worked the best are some of the ones
in which a gel was used. So, picture a model, lit largely from the
side, with small hints of purple along the extreme side of the image.

I don't find it _unattractive_, but it's something I'd just as soon
dispense with.

So - I'm trying to think of a way to replace a color range _smoothly_.
Perhaps lassooing the relevant area, changing the color balance there
alone, and using some sort of light cloning brush in case there's a
demarcation along the lassoo'd area?

Or is it likely just a case of judicious use of color balance and the
brightness/contrast in order to get the desired effect?

I'll try a few things, but I'm not expecting it to be all that
straightforward - simply because the color I want to eliminate is only
alone one edge of the model's face.

If it makes better sense to post a link to a sample image, I'm happy to
do so.

Thanks for all suggestions!

BD

Bill Hilton

2005-10-24, 10:15 pm

> BD writes ...
>
>I'm trying to think of a way to replace a color range _smoothly_.
>Perhaps lassooing the relevant area, changing the color balance
>there alone

The quick and dirty way to do this is Image > Adjustments > Replace
Color, use the eye droppers to select a color range, vary the
'fuzziness' slider to expand/contract your color selection, and then
vary the hue/sat/lightness sliders at the bottom to change just the
selected colors.

A better way that's more flexible but slightly more work is to do
Select > Color Range and make a color selection with the same type of
eyedropper tools. Once you have the selection to taste click OK and
then open an adjustment layer of type Hue/Saturation. The selection
you just made becomes a layer mask for the adjustment layer so you can
change hue/sat etc in just the selected areas. The advantage of this
approach over Replace Color is that you can re-open the adjustment
layer and tweak it or you can edit the layer mask.

The Help files for Replace Color and Select > Color Range are pretty
good if you want to read up on the nitty gritty.

>I'm not expecting it to be all that straightforward - simply because
>the color I want to eliminate is only alone one edge of the model's face

It's pretty easy once you isolate and select the color ... sometimes
selecting the color is not so simple if there are subtle blends between
colors but once you get the color range selected it's easy enough.

Bill

tacit

2005-10-24, 10:15 pm

In article <1130195849.752774.122790@f14g2000cwb.googlegroups.com>,
"BD" <bobby_dread@hotmail.com> wrote:

> So - I'm trying to think of a way to replace a color range _smoothly_.
> Perhaps lassooing the relevant area, changing the color balance there
> alone, and using some sort of light cloning brush in case there's a
> demarcation along the lassoo'd area?

The lasso is far too crude for something like this. Use Select->Color
Range instead.

You may be able to change the color without using a selection at all by
using Image->Adjust->Selective Color.

> Or is it likely just a case of judicious use of color balance and the
> brightness/contrast in order to get the desired effect?

Do not use Color Balance and Brightness/Contrast for *anything*.

The Color Balance and Brightness/Contrast commands are "linear"
commands. They degrade the quality of the picture, because they clip
detail from hilights and shadows.

Use Curves instead. Curves can do everything Color Balance and
Brightness/Contrast can do, and a lot more besides, but Curves does not
degrade the image by clipping hilights and shadows.

--
Art, photography, shareware, polyamory, literature, kink:
all at http://www.xeromag.com/franklin.html

2005-10-25, 3:14 am

I'll try that.

Thanks to both for the suggestions - might save me from having to
reshoot. ;-)