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Photoshop Channel concepts: The Power of Ten

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  #1  
Old 06-10-2007, 12:22 PM
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Graphics23 Graphics23 is offline
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Post The Power of Ten

An introduction to the concept of viewing every image as having ten channels. [details]
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  #2  
Old 06-12-2007, 09:13 AM
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DannyRaphael DannyRaphael is offline
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Re: Photoshop Channels: The Power of Ten

Thanks for your efforts here. Great concept and illustration. Clear and well written, too.

FYI: I changed the title of this thread for better visibility.
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Old 06-29-2007, 10:43 PM
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Re: Photoshop Channel concepts: The Power of Ten

Here's an action for setting up a ten channel workflow.

You can start in any mode except Bitmap, Duotone, or Multichannel.

It'll take a file and create a duplicate.
The dup is converted to your working RGB and labeled RGB.

It'll go back to the original and dup it again.
This dup will be converted to LAB and labeled as such.

Back to the original and dup it one last time.
This dup is converted to your working CMYK and also labeled.

The original image is left unchanged.

This is a great way to become accustomed to what the various channels look like. Gaining an eye for this is an extremely useful skill since it can benefit just about anything one does in Photoshop.

I use this Action when I want to quickly explore what the ten channels have to offer. Quite often I find the start of a mask or an idea for channel blending that might not jump out at me right away.

As my eye becomes more experienced at inspecting channels I've noticed that ideas suggest themselves to me in ways which I most certainly wouldn't have considered previously.

For example, the other day I was working on an image where I wanted to increase the contrast between subject and background. After running the Ten Channel Action I noticed that in the A channel of LAB the subject was light and the background dark. After a quick blend of the A into the L using Overlay mode I got just what I was looking for.

Enjoy,

Michael
Attached Files
File Type: zip Channels.zip (448 Bytes, 375 views)

Last edited by Graphics23; 06-30-2007 at 11:13 AM.
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Old 06-30-2007, 06:24 AM
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Re: Photoshop Channel concepts: The Power of Ten

Updated tutorial.

Added comments regarding Contrast and Color.

Regards,

Michael
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Old 06-30-2007, 04:08 PM
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DannyRaphael DannyRaphael is offline
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Re: Photoshop Channel concepts: The Power of Ten

Quote:
Originally Posted by Graphics23 View Post
Here's an action for setting up a ten channel workflow.
Great use of automation applied to an enlightening tutorial. A+.

Many thanks again, Michael.
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Old 07-31-2007, 02:44 AM
wallykid wallykid is offline
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Re: Photoshop Channel concepts: The Power of Ten

Hi Michael,

I know this thread very old but I decided I would try it anyway. I will also post this message on a new tread.

This is my first ever message on this discussion board. My question regards PhotoShop modes.

I am an aspiring photographer who is in the process of designing a website to display and sell some of my work. I therefore use PhotoShop to enhance my images for both web/monitor display and print display.

So my basic question is which mode should I work in? I originally thought this would be an easy question to answer, but the more research I do the more questions I have and the more I think maybe I have to work in more than one mode. On this website recently I read some interesting discussions about the 10 channel theory whereby you work on all channels in RGB, LAB and CMYK modes. I’ll be honest. This nearly made me cry!

Here is my dilemma. I am primarily a photographer so I don’t want to spend hours working in PhotoShop. I don’t find this part of the photography process nearly as satisfying as actually taking the photographs. I do realize its importance though and as a result I am very proficient in PhotoShop. I don’t mind studying new and difficult techniques, as long as they are the right ones for my purposes.

My preferred mode for enhancing for web/monitor display is LAB mode. I know however that for best print display quality I should work in CMYK mode.

Does this mean I have to have 2 separate processes for every image (surely there is a more efficient way) or can I start in LAB and then convert successfully to CMYK?

I know LAB mode has a very wide Gamut range and that converting to CMYK will lose some colour details. But these wide Gamut range colours can’t be displayed on a monitor anyway so is there any real point of working in LAB?

My latest workflow theory is that I could:
• Start my enhancing in LAB (colour, contrast, some masking etc..)
• Save file.
• For web/monitor display stay in LAB and sharpen. Finally convert to RGB to save for web.
• For print display convert to CMYK mode fine tune highlights/shadows and sharpen.

But would this workflow plan result in vastly different results. My aim is to keep my photos on the web the same as the photos I print. Both being of the best quality possible.

Or should I do all my work in CMYK and then convert back to RGB to save for web. Is CMYK as easy and effective as LAB for general image enhancing.

Too many questions! So if anyone out there has any suggestions or advice I would appreciate it very much. I’d even buy you a beer if we ever met!

Take care,

Conor
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Old 07-31-2007, 06:26 AM
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Re: Photoshop Channel concepts: The Power of Ten

Hey Conor, welcome to RetouchPRO!

You ask; which mode should I work in?

Work in the mode that gives you the best technique to achieve your goal. That's the whole point of this article. All three modes have strengths and weaknesses. Taking advantage of the strengths and avoiding the weaknesses is the important thing.

It depends on the image. Your photographs will be starting out in RGB. If there's nothing to be gained by converting to LAB or CMYK, why do so?

I'm a prepress technician. In the exciting world of digital prepress, time is money. I can't afford to spend hours working in Photoshop, so I'm always looking for the most bang for my buck!

If an RGB curve gets the job done, great! But if I need more color variation, then I'm converting to LAB.

If a channel blend gives me what I need, super! But if a quick sharpening of the blacK channel makes the image pop, then it's CMYK and I'm done.

You state your preferred mode is LAB. Why? LAB is like a sledge hammer. You can't tap in carpet tacks with a sledge hammer! And just because printing is done in CMYK doesn't mean YOU "should work in CMYK mode". You should work in CMYK mode if that channel structure will give you the most leverage to move your pixels.

You should have one RGB image which is properly tagged. Convert this image to sRGB for web display and provide it as is to your printer after explaining that you have tagged it for color management and the tag should be honored. Then let the printer handle the conversion to CMYK.

This is also important when printing to your inkjet printer. Most inkjets expect RGB. If you send it CMYK, most likely it will convert to RGB and then convert again to CMYK.

LAB has a wide gamut, yes. But converting to CMYK won't loose any data if there's nothing in your image that's outside of the CMYK gamut. This general fear of converting due to lose of data strikes me as jumping at shadows. I convert when necessary and very seldom have I ever had gamut issues. Especially going from RGB to LAB and back. When I do have gamut issues there are workarounds.

Don't get hung up on color modes. They all have their place. Keep an open mind and try to remain flexible. As you gain experience things will sort themselves out.

Regards,

Michael

Last edited by Graphics23; 07-31-2007 at 08:45 AM.
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Old 07-31-2007, 08:22 AM
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Richard_Lynch Richard_Lynch is offline
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Re: Photoshop Channel concepts: The Power of Ten

Michael...
Interesting. One of the things I have done in books of mine is show how to work with CMYK in RGB mode by separating out the CMYK components based on light theory. I also, in my new book, show how to work with channels as layers -- so that there is really no need for two palettes, AND you have more flexibility with the changes that you make.

In general this type of thing is something most people need to know more about.
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  #9  
Old 07-31-2007, 10:48 AM
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Re: Photoshop Channel concepts: The Power of Ten

Hi Richard,

Thanks for chiming in!

Using channels as layers sounds very intriguing.

As you can surmise I'm something of a channel junky, so I'd very much like to discuss the concept.

I'm at a point where finding a new book on Photoshop has become very difficult. At the risk of tooting my own horn, most books simply don't speak to my level of experience. I have no interest at all in another book by "The Photoshop Guys" or any of the myriad recipe type offerings.

Other than works by Dan Margulis, I haven't found anything in quite some time which sparks my interest and also challenges me.

Would your "Layers" book be something an old timer like me find worthwhile? Perhaps if you elaborate on the channels as layers idea you might entice me into buying your book.

Regards,

Michael
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  #10  
Old 08-01-2007, 12:23 AM
wallykid wallykid is offline
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Re: Photoshop Channel concepts: The Power of Ten

Hi Michael,

Thank you very much for your detailed explanation. I really do appreciate it. It has helped me a lot. Sorry to take up more of your time but I would like to ask you about the following section of your answer:

“You should have one RGB image which is properly tagged. Convert this image to sRGB for web display and provide it as is to your printer after explaining that you have tagged it for color management and the tag should be honored. Then let the printer handle the conversion to CMYK.”


My first question is about the term “tag for color management”. What do you mean by this? Is it a PhotoShop process or tool? I have looked in the PS help and found nothing. I then did some Google searches but can’t find anything helpful that explains what you might mean.

My second question is about PhotoShop working spaces. I was under the impression that for web/monitor output the sRGB working space should be used, but for print output Adobe RGB working space should be used. In one of my PS books it even says avoid using sRGB for print output. But you seem to suggest that working in sRGB is okay for printing.

This is your field of expertise so I would be really interested on what you have to say.

Take care,

Conor
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