RGB to CMYK – Cyan channel is allways without detail

DG
Posted By
Diogo_G
Mar 12, 2007
Views
408
Replies
7
Status
Closed
Hi all

I recently started to work on a newspaper, dealing now with digital cameras from several photographers free-lancers.

It seems that compared to scanners the Cyan channel is missing detail or has less "hi-fi" definition.

Tried several cmyk color profiles, the renderings with and without the black point compensation.

Is this a normal behaviour? Is possible to regain the cyan detail?

Thanks

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PF
Peter_Figen
Mar 13, 2007
What does your red channel look like in the RGB? There is no inherent reason for your cyan channel to be lacking unless there is nothing there to begin with, or you have a very weird profile for CMYK, but since you claim the same file looks lacking with several profiles, you may have other problems. How are your files printing? That’s the more important question.
DG
Diogo_G
Mar 13, 2007
Hi Peter

Files are raw. The red seems to have good detail; by itself it will do a good gray image. When converted to "generic profiles" (like euroscale and others from Adobe)turns to muddy or blurred details.

And they are printing fine, but we do a lot of work with commands like channel mixer or a copy/paste of the red in the cyan channel (and using the fade command with blends) to preserve a good shape in the channel.

With faces (skin tones) this lossy detail make the image appears to have a lack of volume, detail, definition.
PF
Peter_Figen
Mar 13, 2007
How are you processing the raw files into tiffs? How do the RGB files look on a calibrated screen? What do all the individual channels look like?

The generic profiles from Adobe are only good for the conditions they were designed for, and your conditions may be vastly different from those. If your RGB looks good, but your CMYK sucks, you can pretty much point toward the profile or conversion. You shouldn’t have to make complicated changes as a matter of course, only when you have extraordinary circumstances like areas of super saturation where you might want to retain more detail.
DG
Diogo_G
Mar 13, 2007
I used the generic profiles from Adobe as a clear example of the experiment. The screen is ok and all the MYK channels seems to to have good detail. Usually I would expect in the C channel something similar to the K but with less ink (brighten).

Most of the times I have a very different C and with "flat" zones without detail. I didn’t find a behaviour pattern in the saturated areas; is the detail, draw, HI-FI information that is missing.

The composite image looks well, but when in the final print this images tends to be flat, specially the faces.
B
Bernie
Mar 13, 2007
when in the final print this images tends to be flat, specially the faces.

Are you sure that you are converting to the proper CMYK profile to begin with?
PF
Peter_Figen
Mar 13, 2007
I don’t remember seeing any newsprint profiles as part of the Adobe icc set, so it’s very likely that the profile you are using are not right for your intended output. You would be best off normalising your newspaper press run and making a custom profile from that – one that had the right black generation and ink limits for your output.
DG
Diogo_G
Mar 14, 2007
we use IFRA profiles for the newspaper. That is not the point; I mentioned the generic profiles as an example, because de behaviour of the C channel also occurs with the Adobe profiles.

But, if nobody else see the same problem I need to buy another pair of glasses… 🙂

Thanks guys

MacBook Pro 16” Mockups 🔥

– in 4 materials (clay versions included)

– 12 scenes

– 48 MacBook Pro 16″ mockups

– 6000 x 4500 px

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