Taiwanese Wreath

[mikemeister_admin]

A little lost on this correction as well Greg . . . but here it is.

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There are a couple of interesting things that happen with this image in CMYK (also know as wgCMYK) color space.  One is that you can control the contrast in the extremely colored areas by changing the curve for the opposite color.  For example, play with the cyan channel to add more color to the red flowers. 

Another thing that CMYK can do for you is give you control over the shadows - in this case you can reduce the shadow by modifying the K channel.

I'd be interested in your experience with this example.  I notice that you used an Lab curve, to get some very saturated colors indeed.  Using the clock, I notice that the tree on the right is somewhere between magenta and red - this should be either neutral, or tending toward orange-yellow.

[mikemeister_admin]

Hi Mike:

I am a bit of a klutz when it comes to RGB and CMYK which seems to be a lot like RGB with an additional K channel to add black.  Obviously Lab is the "go to" color space because it is more intuitive (a nice word for easier) to use, but I am beginning to understand that it has its limitations for fine corrections so I am trying to get better with RGB and I suppose that would mean CMYK by extension, though I don't expect I will ever need to do any prepress work.  I am still struggling a bit with non-Lab corrections though, and after playing around with the image in CMYK a bit (and ending up with a magenta tree -- thought I got that fixed!) found that I could do a better job starting with Lab and then using Greg's hint with Cyan to control the shadows a bit.  If CMYK is a useful tool to have in the drawer it might be a nice subject to concentrate on in a side tutorial or more advanced class because I know we don't work with it much in CM101.

In the end, I think I just got tried and sloppy last night, so I need to take another stab at this image, which I will probably do today.

Brian

[ggroess]

Brian,
CMYK is hard to get at first if you have never played in that space.  It is much more subtle for corrections..I use that word alot this class...lol...

I always think of CMY as a Negative RGB. the K space is what gives the image depth.  In the press world the k is black ink and black is a cheaper alternative to turning up the other colors.  If you take equal parts of C, Y, M  you will get a neutral just as equal parts of R, G, B give you a neutral.  But in CMY it will lack fullness and depth.  When you add the K you can turn down the other colors a bit and still keep the same look.

Another way of looking at it is that RGB is like theater lighting.  The more light you have the closer to white light you get. if you add Red and Green and blue light together you get white light.  If you add Cyan, Magenta and Yellow together you get a dark gray.  It's the same problem in CM.  Sometimes I will take an image into CMYK for a single color.  It is easier to control in there...the beauty of CM is that you can do those things without all the fancy mode switching in PS.  You just have to be aware that there is a conversion and the LAB values can easily be out of gamut for CMYK.

Greg