In Photoshop there are 2 different method to show out of gamut. The first is Select -- Color Range and set the dialog box to "Out of Gamut". The 2nd is turn on View - Gamut Warning.
Can someone explain exactly how these are the same and/or different. I tried both and they show different areas of a picture being out of gamut so they are clearly not the exactly the same, but I can't find a complete, detailed, and specific definition that compares and contrasts them.
Select > Color Range will show the areas outside of the CYMK default you select under Edit > Color Settings (e.g. SWOP CYMK). View Gamut Warning will show the areas outside of the CYMK profile you select under View > Proof Setup. If you select "Working CYMK" under View > Proof Setup both should show the same areas as being out of gamut.
Yes, that is exactly correct per my own experimentation last night. My follow on question is more conjecture but what is so valuable about this feature and why is it specific to CMYK?
It would more general and more useful if I could select out of gamut based on any profile not just CMYK. This seems to be a historical feature when printing was exclusively CMYK. I often have to pan and zoom to find the little gray pixels shown by Gamut Warning. Having a way to easily select them would be nice.
You apparently don't realize that ALL printing is CYMK at the point where the image is created, even in a photo print which has CYM dye layers.
What differs between photo / ink jet printers and offset printing is when and where the RGB > CYMK conversion is done. With photo printers the conversion is done in the printing device. For offset printing the RGB > CYMK conversion will typically be done in Photoshop with the results being saved as a CYMK TIFF created using the press profile profile, which would apply under-color removal, paper and dot gain compensation. At the time the separate CYMK press plates are created the CYMK color separations are merged electronically with the CYMK page layout application files. The printing industry, encouraged by Adobe, is moving to a PDF based RGB workflow in which everything is kept in RGB until send to the platemaker or digital press. That workflow is more similar to how an RGB file is printed on an ink jet.
That is not true. Many inkjet printers have red, blue, and yellow inks. Regardless, it still seems limiting and useless to limit the seletion to those colors that out out of gamut in some CMYK space. Case in point, proof profiling allows the user to see any out of gamut based on the profile of choice (not limited to CMYK).
I could be wrong but I think the Out of Gamut stuff in Photoshop is considered legacy at this point with soft proofing being the recommended approach. Soft proofing isn't as nifty as those visual cues you get with the gamut warning, but it is considered more accurate. Jeff Schewe did a pretty good explanation of it somewhere a couple months back though I don't have a link handy.
sgirard wrote:
I could be wrong but I think the Out of Gamut stuff in Photoshop is considered legacy at this point with soft proofing being the recommended approach. .
I think you may very well be wrong for Out of Gamut warning can be used in conjunction with soft proofing. Just because soft prof shows you a color it does not mean that the output device can produce it.
After you setup your custom soft proof setting Ctrl+Y toggles between viewing you image with the best colors your display can do and viewing on your display what you image will look like on your output device. And Ctrl+Shift+Y will toggle gamut warning on and off.
Here is an image generated via HTLM and screen captured. Some colors are way out of printers color gamut. Download the image open it in Photoshop setup soft proofing for your printer. View image in soft proof and gamut warning on and off. Then change the soft proof setting for a better printer paper combination. And look at the views again. Soft Proof will show color rams in both cases. The Area shown to be out of gamut will change for each soft proof setting.
I tend to agree that Out of Gamut seems a bit legacy for a couple of reasons. The 1st is that CMYK is no longer the exclusive print method. It also that cast that soft proofing with CMYK as give you the same result as Out of Gamut. The only issue I have with soft proofing is that it can sometimes be exremely difficult to find all the pixels that out of gaumt.
Mr Mouse wrote:
Just because soft prof shows you a color it does not mean that the output device can produce it.
Maybe not quite a 100% accurate view, but that is basically the point of soft proofing isn't it? The profile describes the gamut which your device/paper/ink combination is capable of and soft proofing maps your source to that destination space. I'm guessing when you toggle the overlay in proof view you're just seeing which areas have been affected by the rendering intent you have chosen? The soft proof should still be an accurate representation of what you will actually see in print (so far as such a thing is possible).
I think the issue some people have with the gamut warning feature (which I'm almost sure predates soft proofing) is that it is an all or nothing overlay. For example It might show most of an image out of gamut when the reality is that all but a small area - or even the entire image - might map very well with the proper profile, rendering intent, etc. - close enough say as to not be a concern. So you see a theoretical problem space but don't necessarily see where your actual problem areas are. That's not to say people can't get mileage out of it.
I may have inadvertently steered the thread a bit off topic... sorry! I don't know the answer to the original question, but Chuck's response at the beginning sounds good to me.
