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#1
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Working space and Colorvision Profiler Pro
Hi,
I'm using Profiler Pro V2.3 to profile my Epson 2200. In the documentation, it says that during profile creation, the working space in Photoshop should be the same as the working space that will be used afterwards, while editing and printing images. It also says that it is important to always use this same working space, because otherwise there will be a colour shift. This makes sense - I have read elsewhere that profiles are (or can be) to an extent optimised for a particular source gamut. This is all fine, except that what I'm noticing is that the resulting profile seems to behave identically, *regardless* of the working space I use while building the profile! Has anyone else noticed this? Should I tag all the Profiler Pro ancilliary images (the images it opens up during the profiling, and which are tagged by default with Adobe RGB) with my new working space? Should I *convert* them all to my working space? I am in touch with Colorvision support as well, but so far they don't even seem to understand what my issue is. Thanks, Greg. |
#2
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Greg wrote:
Hi, I'm using Profiler Pro V2.3 to profile my Epson 2200. In the documentation, it says that during profile creation, the working space in Photoshop should be the same as the working space that will be used afterwards, while editing and printing images. It also says that it is important to always use this same working space, because otherwise there will be a colour shift. This makes sense - I have read elsewhere that profiles are (or can be) to an extent optimised for a particular source gamut. This is all fine, except that what I'm noticing is that the resulting profile seems to behave identically, *regardless* of the working space I use while building the profile! Has anyone else noticed this? Should I tag all the Profiler Pro ancilliary images (the images it opens up during the profiling, and which are tagged by default with Adobe RGB) with my new working space? Should I *convert* them all to my working space? I am in touch with Colorvision support as well, but so far they don't even seem to understand what my issue is. Photoshop is designed to recognize embedded profiles, and honor them for printing and display purposes. The end goal of this is consistency, which is what you are seeing. There are ways to thwart this - for example by selecting the "Same as source" option in the print dialog, and this may well be what the Colorvision folks are refering to. For more detail, see: http://www.computer-darkroom.com/ps7_print/ps7_print_mac_2.htm -- Mike Russell www.curvemeister.com www.geigy.2y.net |
#3
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"Mike Russell" wrote in message
om... Photoshop is designed to recognize embedded profiles, and honor them for printing and display purposes. The end goal of this is consistency, which is what you are seeing. I understand this. When I said "identical results", I mean *exactly* - the resulting pixel values are 100% identical. This doesn't make sense to me at all. If Colorvision really mean what they say, then when I build two different profiles (using two different working spaces during the profile creation), I would expect at least the perceptual tables to produce slightly different colours, when I switch between the two profiles. It appears to me that it makes no difference whatsoever what my working space is set to during profile creation - this is contrary to the Profiler Pro documentation. Greg. |
#4
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Greg wrote:
"Mike Russell" wrote in message om... Photoshop is designed to recognize embedded profiles, and honor them for printing and display purposes. The end goal of this is consistency, which is what you are seeing. I understand this. When I said "identical results", I mean *exactly* - the resulting pixel values are 100% identical. This doesn't make sense to me at all. If Colorvision really mean what they say, then when I build two different profiles (using two different working spaces during the profile creation), I would expect at least the perceptual tables to produce slightly different colours, when I switch between the two profiles. It appears to me that it makes no difference whatsoever what my working space is set to during profile creation - this is contrary to the Profiler Pro documentation. Perhaps the documentation is not correct in this respect. This is the way I see it: First you print a color chart. It shouldn't really matter in which color space you opened that chart, because in the end you will print it in the *printer color space*. That's all the printer can do. Next you measure the results by scanning that print. You build the profile based on that, so I don't see any reason why the profile should be different if the color space of the chart is different. As long as you do not "Convert to profile" when you open the chart, the RGB values you get (and so the RGB-values you sent to the printer) are identical, no matter what color space you used. -- Johan W. Elzenga johanatjohanfoto.nl Editor / Photographer http://www.johanfoto.nl/ |
#5
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"Johan W. Elzenga" wrote in message
... Perhaps the documentation is not correct in this respect. I've been kind of wondering whether this might be the case. This is the way I see it: First you print a color chart. It shouldn't really matter in which color space you opened that chart, because in the end you will print it in the *printer color space*. Agreed/understood. That's all the printer can do. Next you measure the results by scanning that print. You build the profile based on that, so I don't see any reason why the profile should be different if the color space of the chart is different. As long as you do not "Convert to profile" when you open the chart, the RGB values you get (and so the RGB-values you sent to the printer) are identical, no matter what color space you used. I have read that it is possible to optimise the perceptual intent tables for different assumed *source* gamuts. For example, if the source gamut is large (e.g, Ekta Space), the perceptual conversion needs to scale the gamut down much more than if the source gamut is small (e.g, sRGB). This is what I thought Profiler Pro might be trying to do - optimise the perceptual tables for the user's working space. So, by some means, I thought the Profiler Pro plugin might have determined what the current working space is (during profile creation), and taken that into account while actually building the profile. The documentation is very clear in it's directive to set the working space during profile creation to whatever working space will be used afterwards. But as you say, it may just be incorrect. Greg. |
#6
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"Johan W. Elzenga" wrote in message
... As long as you do not "Convert to profile" when you open the chart, the RGB values you get (and so the RGB-values you sent to the printer) are identical, no matter what color space you used. Also, note that other images (two, I think) are opened by Profiler Pro, *during* the profile creation. I don't think these images are important - I think Profiler Pro just needs *any* image open for certain operations, simply because it's a Photoshop plugin. These images are tagged with Adobe RGB, and the documentation clearly says not to convert them when opening. (i.e, to leave them in Adobe RGB). Greg. |
#7
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Greg wrote:
"Johan W. Elzenga" wrote in message ... As long as you do not "Convert to profile" when you open the chart, the RGB values you get (and so the RGB-values you sent to the printer) are identical, no matter what color space you used. Also, note that other images (two, I think) are opened by Profiler Pro, *during* the profile creation. I don't think these images are important - I think Profiler Pro just needs *any* image open for certain operations, simply because it's a Photoshop plugin. These images are tagged with Adobe RGB, and the documentation clearly says not to convert them when opening. (i.e, to leave them in Adobe RGB). I can understand that you shouldn't *convert* anything. That makes sense. Let say that the color chart contains a patch with RGB values 200,200,200. You print this on your printer and next you scan this print. The scan will be opened in your default color space, so that will be AdobeRGB. Because the original chart was in AdobeRGB as well, the software can make a direct comparision: The scanned patch should be 200,200,200 again, but it won't be. The difference is what is used to make the profile. However, if you opened the chart and used "Convert to profile" in order to use another color space, the original patch value would not be 200,200,200 any longer. It will be converted to something else, so you printed something else. Scan this into AdobeRGB, and you obviously find a value that is not 200,200,200. Not because of the printer, but because the value wasn't 200,200,200 to begin with. The result is that your new profile will be off. By the way, it seems that Profiler Pro works a little differently from the one I got. I have PrintFIX and DoctorPRO. PrintFIX doesn't open any other image during profile creation. DoctorPRO does open an image during profile correction, but that seems indeed because something has to be open (DoctorPRO runs an action, that can't run if there's no open document). -- Johan W. Elzenga johanatjohanfoto.nl Editor / Photographer http://www.johanfoto.nl/ |
#8
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"Johan W. Elzenga" wrote in message
. .. By the way, it seems that Profiler Pro works a little differently from the one I got. I have PrintFIX and DoctorPRO. PrintFIX doesn't open any other image during profile creation. FWIW, I've just tried it again, and it opens an image called "Colorvision.tif" twice - once when I open the measurements file, and once when I click the ok button to generate the profile. The image is the colorvision logo. DoctorPRO does open an image during profile correction, but that seems indeed because something has to be open (DoctorPRO runs an action, that can't run if there's no open document). Indeed. Greg. |
#9
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Greg wrote:
"Johan W. Elzenga" wrote in message . .. By the way, it seems that Profiler Pro works a little differently from the one I got. I have PrintFIX and DoctorPRO. PrintFIX doesn't open any other image during profile creation. FWIW, I've just tried it again, and it opens an image called "Colorvision.tif" twice - once when I open the measurements file, and once when I click the ok button to generate the profile. The image is the colorvision logo. Could well be that this is for entertainment only. Personally, I can't see why the Colorvision logo would be needed to create a profile! -- Johan W. Elzenga johanatjohanfoto.nl Editor / Photographer http://www.johanfoto.nl/ |
#10
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