A place to seek advice and answers on those particularly challenging issues.
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I have been asked by a fellow member if I could help in explaining channels. The question stemmed from an attempt to follow Katrin Eisman's book on restoration to deal with faded old photos from the 70s (with Elements 6.0).
I am fond of channels... and I have been guilty of posting several times on the subject. On the other hand, like most of you, I would be very happy to help friends in this forum.

Now, you can imagine what a challenge that may be:
- I have not read Katrin Eisman's book (I know it is considered a must in restoration)
- A complete explanation of channels could require a thick book
- Channels are not directly available in Elements
- Channels may or may not be the way to restore faded photos (a sample would be necessary)
- Even exploring channels for a better understanding is not an obvious task for a forum, it would need too much space, even for the newsletter.

However...

- I am convinced that a better understanding of channels may be helpful to all, including for creative purposes, not only for black and white conversion...
- I am positive that even without the full photoshop you can go a long way with channels in Elements (thanks to Richard Lynch... with or without his tools)
- This forum is interactive, which is not the case of a tutorial, even for the newsletter. Everyone may ask a question... or give an answer
- I think the best way would be to introduce channels progressively, with useful examples

Before I start a first post on this subject, here are two interesting links for advanced users, who are welcome to help me in this task:

http://www.retouchpro.com/forums/rp-tut ... r-ten.html
http://www.normankoren.com/light_color.html
Michel B
PSE6, 11,12,13.1 - LR 5.7 Windows 7 64 - OneOne Photo Perfect Suite - Canon 20D, Pana TZ6 - Fuji X100S
Most used add-ons: Elements+


Mes Galeries
Thank you, Michel. Channels are a mystery to me. I have Graffi's!!
Thank you Michel. My question is regarding the use of Graffi's channel actions on a colored photo. If, for instance, I look at the individual channels in a colored photo, I get to see a black and white image on my screen. On some, I can clearly see that noise or other damage is in one particular channel. How can I correct only that particuar channel and come up with an improved color image. I don't know if I am making myself clear. It would be helpful to me if you can demonstrate how this can be accomplished. Thank you so much for putting the time and effort into helping me to understand this.
Elaine
Elaine,
This clarifies your needs...
Let me be basic for beginners who might be interested by channels, and then I'll come to your problem: what to do with the channels and foremost, how to recombine them.
A good introduction is shown in the PrestoPhoto help:
http://www.prestophoto.com/wiki/Understanding+Color

Since Newton and Maxwell, we know that the full spectrum of colors can be reproduced by combining 3 basic colors in various proportions. The RGB representation: Red, Green and Blue is the additive system, which was used first to produce color photographs (Ducos du Hauron and Charles Cros, 1868). The principle was to shoot 3 different photos, each one with a different coloured filter, and have 3 projectors with the same filters to recombine them. Maybe there are people here who practiced color darkroom. The trick was to put the right density filter in the enlarger for red, expose, then do the same with green and blue when an additive process was required.
As explained in the above mentionned tutorial, the substractive system is that of painting or printing where pigments absorb light radiations instead of reflecting them. CMYK is the name for this: Cyan, Magenta, Yellow and black. If you have seen small Kodak printers printing successively the four colours, this is pretty obvious. In the darkroom, instead of exposing 3 times red, green and blue, a stack of cyan, magenta and yellow filters were used in a single 'substractive' exposure.

Now, if you know how to extract channels (with Grafi's tools or as explained in my post: viewtopic.php?f=5&t=1573), your problem is first to know how to cure or compensate a given channel, then how to recombine them. Please wait for another post for an explanation with illustrations.

You might think the trouble with faded photos lies with the fading of one of the CMYK components used in your old prints, and that working in CMYK mode, like in the full photoshop is necessary. You'll see that this is not a problem, and that Elements can provide you with the required tools in RGB.

Where are channels in Elements? As a matter of fact, only levels, and the black and white conversion let you target the R,G,B channels. Hue saturation works on the resulting hues, not on the channel. However, you can use a layer setup which mimics the three projectors.

The grey color components layers are in screen mode, the color ones are in multiply mode. You can work with a component layer (denoise, sharpen, blur, mix with another component...)

What kind of adjustment will depend on your pictures.
RGBLayers.jpg
RGBLayers.jpg (49.08 KiB) Viewed 1891 times
Michel B
PSE6, 11,12,13.1 - LR 5.7 Windows 7 64 - OneOne Photo Perfect Suite - Canon 20D, Pana TZ6 - Fuji X100S
Most used add-ons: Elements+


Mes Galeries
Michel,
I also would like to thank you, I have been trying to understand channels for awhile. Have Graffi's channels, would love to know how to use it. posting.php?mode=reply&f=5&t=2345#
:thanks:

Ina
Michel, it has been posted in the newsletter suggestions thread a series on using Channels. It has also been mentioned asking you if you would be willing to take on such a thing.

Kim
My Creations
Canon 40D, Canon 28-135mm IS lens, Canon 300D, Canon 18-55mm lens, CS3


Kimz Kreationz Blog
AngelicKim wrote: Michel, it has been posted in the newsletter suggestions thread a series on using Channels. It has also been mentioned asking you if you would be willing to take on such a thing.

No problem, I have answered positively to this post... Now, a forum is interactive, that's why questions, comments and additions are welcome! Just like color management cannot be explained in two pages, channels need some patience to be mastered, but that's possible even in Elements. And it will be useful too to Photoshop users.
Michel B
PSE6, 11,12,13.1 - LR 5.7 Windows 7 64 - OneOne Photo Perfect Suite - Canon 20D, Pana TZ6 - Fuji X100S
Most used add-ons: Elements+


Mes Galeries
Thanks Michel, I left a post in the other thread.

Kim
My Creations
Canon 40D, Canon 28-135mm IS lens, Canon 300D, Canon 18-55mm lens, CS3


Kimz Kreationz Blog
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