CM Week 2 Example 4 Wreath

[dkrassen]

Hello.

I experimented with this image in CMYK in the manner recommended by the hint provided.  I am finding the CMYK option more confusing than the others.  Please try to further explain it.  Also, I see some improvement in the adjustment I made but would like your opinion on what I should have done differently.

Thank you
David

[ggroess]

David,
CMYK is difficult for many people because you have to think in inverted colors.  RGB is what we think about alot...the color opposites are CMY.  For instance, Your shadows are too red.  I adjusted the Cyan channel and the K channel to fix that.  Why?? Cyan is the color opposite of Red.  If you had a true Cyan Cast in RGB you would correct the Red channel to fix it...

Also, keep in mind that CMYK is ink on paper.  We see it on the monitor the same as RGB or LAB but...the corrections are being applied to simulate ink on paper.  It appears to take bigger adjustments to make a difference in CMYK.  This just gives you more adjustment room in overall effect.  It is a subtle color space, it requires a bit of thought...

The K channel is a major part of the color space...It allows you to use less ink for the same tonality.   

CMYK is called a Subtractive Process because it subtracts from the light being reflected off the page by blocking it with colored inks.  As more and more ink is added the image gets darker and darker.  Cyan, Magenta and Yellow when combined make a flat grayish or even slightly brown color.  It is for this reason the black ink is added to the mix to help “complete” the images.

Some very sound reasons for The K in CMYK are:
• The Black is used for printing text.  It also helps with density in images.
• If you have 100% ink coverage on the pages they can take too long to dry or the ink can bleed through to other copies when stacked. 
• Black reduces the amount of ink required to get the same density results.
• Black ink is cheaper to produce and use.

The GCR setting is also a part of the problem...The GCR is "Gray Component Replacement"  This is a way for printers to adjust the amount of Black ink overall. it is an adjustment of the "blackness" of the blacks...If you go to the mask cart and look at the K channel you will see that it is different from the L channel...The K channel is based on the Tonality and GCR settings. 

CMYK is really your friend...you just have to get more time in the space to get used to it.  Don't worry if you smack the image around a bit at first...keep playing until you get a better feel for it.

For your image I added K by moving the highlight end of the curve in...this increased the overall contrast and made the shadows darker overall.  I also tried to reduce the color in the shadows a bit...this forced some changes to the other colors to make sure things looked right...

Greg