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Load Luminosity as a selection - How?

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ylustrata

Technical User
Aug 13, 2002
80
US
My textbook says "load the image's luminosity by pressing (Cmd + Option + ~) [Ctrl + Alt + ~] to create the active selection. Loading the luminosity uses the overall image brightness to make the selection." I am running Photoshop 6 and I can't find the command (I hate pressing keys and not knowing what I am doing). I see Select -- Color Range -- but the dialog box does not offer luminosity as an option.
 
There is no menu equivalent for making that selection. It is similar to Ctrl+Clicking on the RGB channel in the channel palette. If the selection is pasted to a layer and used for blending with the original, it is also similar to using a duplicate of the original layer for blending, but with blend-if settings in layer properties set such that bright pixels are 100% included and the rest of the pixels are partially included in proportion to their lightness.
 
Would I get the same effect if I do this:
1. Duplicate the image: Image > Duplicate
2. Image > Mode > Grayscale
3. Image > Adjust > Invert
4. Return to original: Window ....
5. Select > Load Selection (load the negative in step 3)
6. Layer > New > Layer via copy
7. Edit > Fill... 50% gray, Color Burn

I find it extraordinary that there can be a keyboard short cut for a command that cannot be accessed via a menu.
 
What is selected by Ctrl+Alt+Tilde is similar to loading a selection based on the the inverse of a grayscale version. Beyond that, you lost me -- it doesn't need the 50% gray or color burn.

Regards,
Sheri
 
Thanks for your reply. I should have tried it before posting. I got pretty much the same result. All that effort is to correct an overexposed color image or to let Photoshop do what should have been done with a fill-in flash (subject in front of a bright background)
 
A good way to address the missing fill flash is...

Start with a flattened image, with the background layer highlighted in the layer palette.

Ctrl+Alt+Tilde to select luminosity
Ctrl+Shift+I to select inverse of luminosity
Ctrl+J to put the selection on a layer
Change the blend mode of the new layer to screen
Adjust the opacity of the layer.

If its still not bright enough, you can duplicate the screen layer and adjust the opacity.

To deepen shadows use the luminosity selection instead of inverse luminosity and a blend mode of multiply instead of screen.

You can also have one or more of each (screen and multiply) and independently adjust shadows and highlights. If necessary add an adjustment layer for brightness/contrast afterwards and make a conservative boost in contrast afterwards. All of that should work fine in versions 6, 7 and CS of Photoshop but in Photoshop CS you can use the new Shadow/Highlight feature instead.

I wrote some Photoshop actions that work along the lines outlined, you can download them here:


The actions were not tested on Version 6, but I think they will work fine.

Regards,
Sheri
 
Thanks for your reply. Very useful info. Best Regards.
 
I tried to give you a star but my pop-up blocker didn't let me. Thanks again.
 
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