Correcting Overexposed Detail Using Channels

[Myphotosoft]

When having a picture with a good overall quality and some flatness in detail you can save the photo with those channels that are not spoiled and have full information. [details]

[Swampy]

Thank you Myphotosoft! Great tutorial that really works.

I did have to hunt around in Photoshop for the "Duplicate Channel" feature. It's one I've never used before, but found it in the Channels Plaette flyout menu.

[palms]

wow this looks like a very useful tut for me any way

Palms

[Lenny]

Hi

I was just trying out this tutorial but I'm slightly confused.

I duplicated the blue channel and saved to a new document.
No I go back to the original image and go to 'apply image' but it doesn't allow to choose this new document with the duplicated blue channel... it does allow me to choose the Blue duplicate layer in the original image.. but it made no difference to the blown out highlight.

Am I missing something obvious here?

thanks for any help you can offer.

:-)

[Graphics23]

Hi Lenny,

It's not necessary to duplicate a layer, a channel, or create a new document to use this technique. However, it's always a good idea to duplicate the Background layer so you're not working on the original pixels.

All you need to do is open the Channels Palette, select the channel you want to edit, then call up Apply Image.

In the tutorial, the objective is to darken the Red channel using the Blue.

So duplicate the Background layer, open the channels palette, select the Red channel, then click on the Eyeball of the composite channel (RGB, at the top) so you can see the changes in full color.

Now open Apply Image:

Source is your working document by default.
Layer should be set to Background.
Channel should be set to Blue.
Target will be whatever you select BEFORE opening Apply Image. In this case the duplicate layer's Red Channel.
Blending should be set to Darken since the objective is to darken the Red Channel.
Opacity should be set to 0%, then increased until you're happy with the results.

By working on a duplicate of the Background layer you can now reduce opacity if you think you went too far, or change the layer's blend mode for different results. For example, setting the duplicate layer to the Luminosity blend mode will darken the image without affecting color.

A final word of caution, be careful when blending with the Blue channel, it tends to be the noisiest of the three. Generally when trying to improve detail in the Red Channel the Green Channel is a better choice.

Good luck,

Michael

[Lenny]

cool... thanks for your comprehensive reply Michael I will give that ago.
:-)

[punkjumper]

Originally Posted by Swampy

Thank you Myphotosoft! Great tutorial that really works.

I did have to hunt around in Photoshop for the "Duplicate Channel" feature. It's one I've never used before, but found it in the Channels Plaette flyout menu.

or even easier, simply right click on the channel.
edit...maybe thats not a mac option