Is color management really needed?

[gordo]

[snip]In a tightly controlled environment with competent hardware, a very good match between monitor and hard copy proof can be achieved that can facilitate critical color adjustment. This usually isn't worth the effort, but I wouldn't say its not possible. I would also say that the softproof is usually subservient to the hard copy proof.

I also wouldn't go as far to say that humans have "no color memory". We do have very poor, and very short color memory, but we can make comparisons between soft-poof to hardcopy nearly as easily as hardcopy to hardcopy, though setting up the former is more difficult.

I don't believe that it is possible to make critical color comparisons between soft-poof to hardcopy because of human biology. You may think it's possible but I believe that's just wishful thinking. That is why, if color is important, press operators will cut the press sheet through the color critical area and overlay the sheet onto the proof to evaluate the match. Having the proof beside the press sheet to make a comparison isn't good enough because of our biology. Using a monitor display to make a color comparison is even more removed.

best, gordo

 

[Deleted member 16349]

Erik If I understood right you are asking Color Picker window of Photoshop
Open a new CMYK document, assign your process profile, open color picker window, pick the color from library then you will see Lab, CMYK and RGB values of the color. For more accurate numbers assign a fresh custom profile. Place the color in document. If your monitor good enough and well calibrated you can see a fair simulation too.

I thought I was asking a simple question but it seems to be causing confusion and maybe because I am not asking it correctly.

I will try again. I suspect that people have difficulty in obtaining separations for offset printing that will result in printing a spot simulation using CMYK screens. I was assuming this is part of the process when using PShop.

As you imply, a custom profile is better than a non custom profile for the output. That would make sense to me. I am not interested in the monitor or proof output for this particular question. I am interested in the press output.

If one is printing to standard densities, and one wants to print a simulation colour for an in gamut Lab colour, can one get a reasonably accurate printed simulation when one uses non custom profiles or similar characteristic data?

There is a lot of talk about the need to have the proof and the print output match. Of course that is important. What I am interested in is how well do the existing methods reproduce an initial target colour.

 

[gordo]

I will try again. I suspect that people have difficulty in obtaining separations for offset printing that will result in printing a spot simulation using CMYK screens. I was assuming this is part of the process when using PShop.
If one is printing to standard densities, and one wants to print a simulation colour for an in gamut Lab colour, can one get a reasonably accurate printed simulation when one uses non custom profiles or similar characteristic data?

There is a lot of talk about the need to have the proof and the print output match. Of course that is important. What I am interested in is how well do the existing methods reproduce an initial target colour.

If the spot color is in gamut you should be able to get within 3 delta E94.

gordo

 

[meddington]

I don't believe that it is possible to make critical color comparisons between soft-poof to hardcopy because of human biology.

I suppose this is somewhat dependent upon the definition of "critical", and I tend to agree that distance is not your friend when comparing color samples (and this would be one of the reasons that a monitor proof would be subservient to a hard copy). I do think, however, that a reasonable comparison can be had within with soft to hard copy distances are minimal, at least for the purposes of determining color adjustment direction. I would also argue that if you have to overlay the proof on the print to see a difference, you're color match is likely very good already. It would be interesting to see a study done in this realm.

 

[Deleted member 16349]

If the spot color is in gamut you should be able to get within 3 delta E94.

gordo

That does not sound too bad. I guess it would be even closer with custom profiles of some kind.

I don't see the need for Kodak Spotless or similar products so much if one can obtain such a close match just with what is already available. If limited to in gamut colours and only CMYK inks.

 

[gordo]

That does not sound too bad. I guess it would be even closer with custom profiles of some kind.

I don't see the need for Kodak Spotless or similar products so much if one can obtain such a close match just with what is already available. If limited to in gamut colours and only CMYK inks.

Although it can be used with just 4/C process, Spotless was developed to primarily be used with an extended process ink set. CMYK printed according to ISO 12647-2 can simulate about 50% of the original Pantone library within 3 delta E94. Of course that's a colorimetric "match" not a spectral match so the simulations may fail or deviate from the actual spot color ink under different lighting conditions.

gordo

 

[Stephen Marsh]

I compared a canned profile and a custom profile of my monitor, and there were some sizable discrepencies. Note that the blues differ not only in saturation, but in hue.

Hi Rich, I too compared the default canned profile to a custom profile.

Although the general size and shape of the gamut follow each other relatively closely, there were of course some discrepancies.

Blue is a good example, simply swapping out the two profiles using the standard “aqua blue” desktop picture, there are noticeable differences in the two blues when viewing the desktop. Of course, this is not the same thing as *softproofing* in Photoshop using a CMYK simulation profile.

When I compared using both profiles in the system and viewing an sRGB image in Photoshop with a photo that had lots of blue in it - softproofing to a CMYK press simulation, the strong visual difference between both profiles disappeared.

My gut feeling is that it makes more of a difference if viewing RGB in isolation or simulating a wider gamut print such as an Epson, however when simulating a standard press condition the differences pretty much disappear.


Stephen Marsh

 

[cosmo]

yes, yes it definatley is, especially on reprints of jobs, they will expect the colours to match the last job, or they will ask for a discount It doesnt really take to much study to figure out colour management on the devices you own, and it teaches you something as well.