filmscanners: which space?
Hi, on a steep learning curve here with scanning and PS6 still a bit befuddled by all the colour management issues.. when I get raw scans from a scanner.. eg Nikon 4000, they don't come in any 'space', right? so should I assign (convert) them to a particular one? isn't that wacking the data right off the bat? if so, which one are most folks using - Adobe RGB or Ektaspace? or another? (I will be doing high bit m/f scans and outputting to inkjets. RGB only, no CMYK repro interest) seems best to start things off how I mean to carry on, so any advice is welcomed. pg
Re: filmscanners: which space?
pg writes ... > ... > when I get raw scans from a scanner.. eg Nikon 4000, > they don't come in any 'space', right? Yes & no ... there is no color space embedded, but every bitmap of RGB values belong to a color space ... you only need figure out which one. > so should I assign (convert) them to a particular one? isn't that wacking > the data right off the bat? "Assigning" will not change the RGB data ... it is the method of choice for finding which color space your raw RGB scans belong to. PS6 will allow you to "assign" color spaces with the preview turned on. Simply go thru all color spaces on your computer, and make note of which color spaces make your scanned RGB look correct. Hopefully, you'll end up with a couple to experiment more with. Essentially, you want to experiment with many scanned images while picking the correct space ... assuming the correct space exist on your computer ... and I'm assuming Nikon gave you one! You will be judging primarily color saturation, but if the reds look good, then inspect green & blue. I would assume Nikon provided you with the correct device profile, and hopefully the assignment should prove obvious. Not having any experience with your scanner, you should have a collection of Nikon device profiles, which you should probably make sure they're in the correct directory so that PS can find them (... if they're in a Nikon directory, then create copies in your "winNT\...\color" directory (... shucks ... I'm not on my NT computer ... search for *.icm files to know exactly where the 'color' directory is ... important: do NOT move the Nikon ICM files, create copies!!! ...) ... anyway ... assigning one of these Nikon profiles should be on the mark. (Hint ... I have no experience (yet!) with Nikonscan 3 (... btw ... let us know if you are using Vuescan ... advice would be different! ...), but scanning "with CMS off" with Nikonscan 2.5 still delivered a gamma inappropriate for what should be raw data ... you need to set application gamma to '1'. If you are using Vuescan, assigning one of the Nikon ICM profiles works for slides only (... I may have some additional info if you are using negatives with Vuescan ...) > if so, which one are most folks using - Adobe RGB or Ektaspace? or another? Most are using AdobeRGB as the working space, but you shoudn't assign this space. You should "assign" the appropriate device color space and then "convert" to AdobeRGB. This will "wack" your data ... but it is necessary if you want to work with AdobeRGB, and you do NOT want your "device space" to be your working space. Bruce Fraser has some excellent advice here for scanner space reccommendations: http://www.creativepro.com/story/feature/8582.html Personally ... I use Vuescan with my LS-2000 and with negatives. I have a device space for "assigning", but it isn't better than simply asking Vuescan for a specific space. I choose to archive and work initially with 12bits in Ektaspace, but these are eventually converted to 8bits and AdobeRGB. I am however anxious to try Nikonscan v.3 ... but it won't be 'til after I've moved lock&stock to Newfoundland in July. shAf :o)
Re: filmscanners: which space?
Paul: I just went through the same learning curve. Try this site and look for the article on setting color management on Photoshop 6 http://www.computer-darkroom.co.uk/ Good luck, Doug - Original Message - From: "PAUL GRAHAM" <[EMAIL PROTECTED]> To: "Filmscanners@Halftone. Co. Uk" <[EMAIL PROTECTED]> Sent: Monday, May 21, 2001 12:09 AM Subject: filmscanners: which space? > Hi, on a steep learning curve here with scanning and PS6 > > still a bit befuddled by all the colour management issues.. > when I get raw scans from a scanner.. eg Nikon 4000, they don't come in any > 'space', right? > so should I assign (convert) them to a particular one? isn't that wacking > the data right off the bat? > if so, which one are most folks using - Adobe RGB or Ektaspace? or another? > > (I will be doing high bit m/f scans and outputting to inkjets. RGB only, no > CMYK repro interest) > > seems best to start things off how I mean to carry on, so any advice is > welcomed. > > pg >
Re: filmscanners: which space?
Hi, Paul-- Although I've read the manual and "Real World Adobe Photoshop," my monitor will not/does not adjust to the Adobe color spaces--or else I'm not dedicated enough to follow it out the window, as it were. Since I record to CD and don't do printouts regularly, sRGB works fine--until I *want* a printout, of course. > (I will be doing high bit m/f scans and outputting to inkjets. RGB only, no CMYK repro interest) I might be misinterpreting here, but I think that outputting to inkjets, or any printing medium, *is* CMYK. RGB and/or the various color spaces are translated and then given to the printer according to the ink colors and abilities available, in that machine's color space--I think. This is what confuses me--CMYK is meant for commercial printing, which is Adobe's strong suit, and the various color spaces are meant for device-coordination as it were (at least, as I read it). But the inks available are still Cyan, Magenta, Yellow, and Black (K, since some would mistake it for "blue" and on some 6-color presses, B *is* blue, and V is varnish). A few processes are only CMY, assuming that the three colors will make black, which in Real Life, they don't--any more than poster-paints can be mixed to produce a reliable brown. What I'm wondering is "Why isn't CMYK adjustment more usable for prints than any RGB color-space?" given that it has to be translated by an algorithm to be applied. The guys at Adobe try to explain, but the guys over at Corel make the CMYK stuff look better on the screen. OTOH, making what's on the screen look like what's on the *print* (or vice versa) is all that's important at the end of the day. I wish that Bruce Fraser would come in here and comment, because I think he knows the answer. Pretty sharp guy, IMO. Best regards--LRA --- FREE! The World's Best Email Address @email.com Reserve your name now at http://www.email.com
RE: filmscanners: which space?
Lynn writes ... > ... > I might be misinterpreting here, but I think > that outputting to inkjets, or any printing > medium, *is* CMYK. RGB and/or the various > color spaces are translated and then given > to the printer according to the ink colors > and abilities available, ... Correct. All desktop printers want to be told to print RGB data, and it's the printer's software which makes the RGB=>CMYk conversion. The printer manufacturers believe they know best, and they probably do ... and it makes it a lot easier for us too ... not to have to worry about tweaking individual ink curves and spot density, and whatever else. In fact if you did need to print to a CMYk device, it would probably be a professional printer, who would want the RGB file, and need only know what color space it was in. If you always used a specific professional printer, you probably should beg him (her?) for a printer profile, so that you could set up "soft proofing" and knowledgeably predict where your RGB was going to end up. > What I'm wondering is "Why isn't CMYK adjustment > more usable for prints than any RGB color-space?" "Real World PS" implies "CMYk spaces are based on the behavior of real physical devices, but the RGB working spaces typically are not." This would imply RGB working spaces are better adapted to device independency. RWPS says elsewhere CMYk spaces are "considerably" smaller than monitor gamuts ... and I believe both of these reasons, taken together, is why no one has developed a device "independent" CMYk working space. > ... > > I wish that Bruce Fraser would come in here > and comment, because I think he knows the > answer. Pretty sharp guy, IMO. Bruce does hang out and is quiet expressive at the Adobe "color management" forum http://www.adobe.com/support/forums/main.html ... it is a link separated from the rest, on the right side of the wwwpage. cheerios, shAf :o)
Re: filmscanners: which space?
When you open an untagged image file in Photoshop 6, you should get the "Missing Profile" dialog. Choose "Assign Profile" and scan the available profiles looking for your scanners profile, then check "and convert to working profile". (You should have previously setup your desired working profile.) Bob Wright - Original Message - From: PAUL GRAHAM <[EMAIL PROTECTED]> To: Filmscanners@Halftone. Co. Uk <[EMAIL PROTECTED]> Sent: Monday, May 21, 2001 12:09 AM Subject: filmscanners: which space? > Hi, on a steep learning curve here with scanning and PS6 > > still a bit befuddled by all the colour management issues.. > when I get raw scans from a scanner.. eg Nikon 4000, they don't come in any > 'space', right? > so should I assign (convert) them to a particular one? isn't that wacking > the data right off the bat? > if so, which one are most folks using - Adobe RGB or Ektaspace? or another? > > (I will be doing high bit m/f scans and outputting to inkjets. RGB only, no > CMYK repro interest) > > seems best to start things off how I mean to carry on, so any advice is > welcomed. > > pg > >
Re: filmscanners: which space?
If I'm not mistaken Bruce Fraser participates in the Epson Inkjets mailing list. Inkjet printers of course print in CMYK but they insist on RGB input and then perform the conversion themselves. So we correct in RGB or CMYK or LAB, whatever fits the bill, but then send to the printer in RGB. Maris - Original Message - From: "Lynn Allen" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Monday, May 21, 2001 10:20 AM Subject: Re: filmscanners: which space? | Hi, Paul-- | | Although I've read the manual and "Real World Adobe Photoshop," my monitor | will not/does not adjust to the Adobe color spaces--or else I'm not | dedicated enough to follow it out the window, as it were. Since I record to | CD and don't do printouts regularly, sRGB works fine--until I *want* a | printout, of course. | | > (I will be doing high bit m/f scans and outputting to inkjets. RGB only, | no CMYK repro interest) | | I might be misinterpreting here, but I think that outputting to inkjets, or | any printing medium, *is* CMYK. RGB and/or the various color spaces are | translated and then given to the printer according to the ink colors and | abilities available, in that machine's color space--I think. This is what | confuses me--CMYK is meant for commercial printing, which is Adobe's strong | suit, and the various color spaces are meant for device-coordination as it | were (at least, as I read it). But the inks available are still Cyan, | Magenta, Yellow, and Black (K, since some would mistake it for "blue" and on | some 6-color presses, B *is* blue, and V is varnish). A few processes are | only CMY, assuming that the three colors will make black, which in Real | Life, they don't--any more than poster-paints can be mixed to produce a | reliable brown. | | What I'm wondering is "Why isn't CMYK adjustment more usable for prints than | any RGB color-space?" given that it has to be translated by an algorithm to | be applied. The guys at Adobe try to explain, but the guys over at Corel | make the CMYK stuff look better on the screen. OTOH, making what's on the | screen look like what's on the *print* (or vice versa) is all that's | important at the end of the day. | | I wish that Bruce Fraser would come in here and comment, because I think he | knows the answer. Pretty sharp guy, IMO. | | Best regards--LRA | | | --- | FREE! The World's Best Email Address @email.com | Reserve your name now at http://www.email.com | | | |
Re: filmscanners: which space?
Maris V. Lidaka, Sr. wrote: > If I'm not mistaken Bruce Fraser participates in the Epson Inkjets mailing > list. > > Inkjet printers of course print in CMYK but they insist on RGB input and > then perform the conversion themselves. So we correct in RGB or CMYK or > LAB, whatever fits the bill, but then send to the printer in RGB. > > Maris > I am still using some of the older Epson printers, so things may be different with the newer models and software. In spite of the fact many, maybe even Epson warns that working in CMYK, and then sending it to the printer causes a double conversion (CMYK, back to RGB to the printer driver, then reconverted to CMYK for final printing), I have been unable to get nearly the control using a RGB output as when I work in CMYK. The control of black ink alone makes it worthwhile. But, overall, my accuracy level goes way up with CMYK output, in my work flow. The one problem is when changes are made in the configuration, Photoshop, version, even specific printer, all best are off, since CMYK is a "locked" mode, while RGB seems to readjust to the new circumstances. I always keep both file types stored. As aside to this, Jon Cone, who runs www.inkjetmall.com sells a huge range of inkjet color profiles, and he also is now providing his new archival inks for a wide variety of Epson printers, including the 3000. The accelerated aging on his inks shows them to be very good. He also sells a wide variety of papers, and his website is quite informative, with links to some other informative locations. I have no personal interest in his company, nor have I ever made a purchase through him, but I think he is doing some ground breaking work in the fields of color management and ink longevity. Art
Re: filmscanners: which space?
We don't disagree - I work primarily in LAB and CMYK myself, for both web and print, but then convert to RGB for final contrast adjustments and to send to the printer. I use Corel PhotoPaint though and an HP printer so I can't comment on Photoshop configuration. I have had good success in matching monitor to print, though not perfect, having merely calibrated the monitor visually. OT: should you ever have the opportunity, please ask Jon Cone to provide archival inks and color profiles for the HP PhotoSmart printer series. Maris - Original Message - From: "Arthur Entlich" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Monday, May 21, 2001 4:50 PM Subject: Re: filmscanners: which space? | | | Maris V. Lidaka, Sr. wrote: | | > If I'm not mistaken Bruce Fraser participates in the Epson Inkjets mailing | > list. | > | > Inkjet printers of course print in CMYK but they insist on RGB input and | > then perform the conversion themselves. So we correct in RGB or CMYK or | > LAB, whatever fits the bill, but then send to the printer in RGB. | > | > Maris | > | | I am still using some of the older Epson printers, so things may be | different with the newer models and software. | | In spite of the fact many, maybe even Epson warns that working in CMYK, | and then sending it to the printer causes a double conversion (CMYK, | back to RGB to the printer driver, then reconverted to CMYK for final | printing), I have been unable to get nearly the control using a RGB | output as when I work in CMYK. The control of black ink alone makes it | worthwhile. But, overall, my accuracy level goes way up with CMYK | output, in my work flow. | | The one problem is when changes are made in the configuration, | Photoshop, version, even specific printer, all best are off, since CMYK | is a "locked" mode, while RGB seems to readjust to the new | circumstances. I always keep both file types stored. | | As aside to this, Jon Cone, who runs www.inkjetmall.com sells a huge | range of inkjet color profiles, and he also is now providing his new | archival inks for a wide variety of Epson printers, including the 3000. | | The accelerated aging on his inks shows them to be very good. He also | sells a wide variety of papers, and his website is quite informative, | with links to some other informative locations. | | I have no personal interest in his company, nor have I ever made a | purchase through him, but I think he is doing some ground breaking work | in the fields of color management and ink longevity. | | Art | | |
Re: filmscanners: which space?
More specific: ICC Color Profiles for Scanners http://www.adobeforums.com/cgi-bin/webx?[EMAIL PROTECTED]^1@.eeb2c3c Mark L From: "shAf" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Monday, May 21, 2001 6:53 PM > > I wish that Bruce Fraser would come in here > > and comment, because I think he knows the > > answer. Pretty sharp guy, IMO. > > Bruce does hang out and is quiet expressive at the Adobe "color > management" forum > http://www.adobe.com/support/forums/main.html ... it is a link > separated from the rest, on the right side of the wwwpage.
Re: filmscanners: which space?
In a message dated 22/5/01 3:05:24 am, [EMAIL PROTECTED] writes: << We don't disagree - I work primarily in LAB and CMYK myself, for both web and print, but then convert to RGB for final contrast adjustments and to send to the printer. >> Dear Maris To the best of my knowledge RGB to CMYK is a one way conversion. CMYK to RGB although possible will cause problems. Although its OK for web use and ink jet printers have you tried litho print when it needs converting back again? Bob Croxford Cornwall England www.atmosphere.co.uk
Re: filmscanners: which space?
That's not exactly the case. What is the case is that a particular Hue, Intensity value - what our eyes perceive as a unique 'color value' can be rendered with multiple combinations of RGB. The same is not true for CYMK So when you map from RGB into ANY color space, you essentially lose some information. Namely you lose the mapping back to the original value settings. That doesn't mean you can't get back to an RGB triplet that will look the same, but it does mean that say if you had set the RGB triplet value to Rx,Gy,Bz then mapped to CYMK and you went back, Rx',Gy',Bz' might not have x=x',y=y',z=z'. This matters because you then can't just 'undo' any filtering you did prior to the mapping. Other color spaces have unique tuplet values. This has to do with the fact that in CYMK, intensity is mapped into the gray-scale K, whereas in RGB, intensity is a function of the particulare RGB values. - Original Message - From: <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Wednesday, May 23, 2001 1:38 AM Subject: Re: filmscanners: which space? > > In a message dated 22/5/01 3:05:24 am, [EMAIL PROTECTED] writes: > > << We don't disagree - I work primarily in LAB and CMYK myself, for both web > > and print, but then convert to RGB for final contrast adjustments and to > > send to the printer. >> > > Dear Maris > > To the best of my knowledge RGB to CMYK is a one way conversion. CMYK to RGB > although possible will cause problems. Although its OK for web use and ink > jet printers have you tried litho print when it needs converting back again? > > Bob Croxford > Cornwall > England > > www.atmosphere.co.uk
Re: filmscanners: which space?
Which is fine by me - so long as RxGxBx look the same as Rx'Gx'Bx' my result will be what I want it to be. Maris - Original Message - From: "Karl Schulmeisters" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Saturday, May 26, 2001 2:23 AM Subject: Re: filmscanners: which space? | That's not exactly the case. What is the case is that a particular Hue, | Intensity value - what our eyes perceive as a unique 'color value' can be | rendered with multiple combinations of RGB. The same is not true for CYMK | | So when you map from RGB into ANY color space, you essentially lose some | information. Namely you lose the mapping back to the original value | settings. That doesn't mean you can't get back to an RGB triplet that will | look the same, but it does mean that say if you had set the RGB triplet | value to Rx,Gy,Bz then mapped to CYMK and you went back, Rx',Gy',Bz' might | not have | x=x',y=y',z=z'. [snipped]
Re: filmscanners: which space?
The complexity comes in when you add translation into another device. Lets say your original RGB values were 128,64,168, then after mapping through CYMK and back to RGB you now have 138,16, 186 (I'm making these numbers up, but they're somewhat believable. Now you want to print to a printer that tends towards green and only takes RGB as input. So you print a test print and low and behold its too green. You only have 16 levels of green left to futz with. From: "Maris V. Lidaka, Sr." <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Saturday, May 26, 2001 11:58 AM Subject: Re: filmscanners: which space? > Which is fine by me - so long as RxGxBx look the same as Rx'Gx'Bx' my result > will be what I want it to be. > > Maris > > - Original Message - > From: "Karl Schulmeisters" <[EMAIL PROTECTED]> > To: <[EMAIL PROTECTED]> > Sent: Saturday, May 26, 2001 2:23 AM > Subject: Re: filmscanners: which space? > > > | That's not exactly the case. What is the case is that a particular Hue, > | Intensity value - what our eyes perceive as a unique 'color value' can be > | rendered with multiple combinations of RGB. The same is not true for CYMK > | > | So when you map from RGB into ANY color space, you essentially lose some > | information. Namely you lose the mapping back to the original value > | settings. That doesn't mean you can't get back to an RGB triplet that > will > | look the same, but it does mean that say if you had set the RGB triplet > | value to Rx,Gy,Bz then mapped to CYMK and you went back, Rx',Gy',Bz' might > | not have > | x=x',y=y',z=z'. > > [snipped] >
Re: filmscanners: which space?
Dear Karl As CMYK is a much reduced colour space compared to RGB I would have thought that made it exactly the case. The true test would be to make multiple conversions from RGB to CMYK and back and see if quality suffered, which of course it does. The real test would be to make the conversion several times in different programmes. R=25%, G=15%, B=10% converts to:- QUARK C25 M50 Y65 K64 PAGEMAKER C56 M74 Y83 K65 FREEHANDC75 M85 Y90 PHOTOSHOP C41 M62 Y69 K70 It all depends on your standards. For LVT output you can't even make one CMYK to RGB conversion without noticing adverse quality; for web use you can probably get away with several. In a message dated 26/5/01 8:29:01 am, [EMAIL PROTECTED] writes: << That's not exactly the case. What is the case is that a particular Hue, Intensity value - what our eyes perceive as a unique 'color value' can be rendered with multiple combinations of RGB. The same is not true for CYMK So when you map from RGB into ANY color space, you essentially lose some information. Namely you lose the mapping back to the original value settings. That doesn't mean you can't get back to an RGB triplet that will look the same, but it does mean that say if you had set the RGB triplet value to Rx,Gy,Bz then mapped to CYMK and you went back, Rx',Gy',Bz' might not have x=x',y=y',z=z'. This matters because you then can't just 'undo' any filtering you did prior to the mapping. Other color spaces have unique tuplet values. This has to do with the fact that in CYMK, intensity is mapped into the gray-scale K, whereas in RGB, intensity is a function of the particulare RGB values. >> Bob Croxford Cornwall England www.atmosphere.co.uk
Re: filmscanners: which space?
Firstly, if the results were as per your example I would look for a new RGB-CMYK and/or CMYK-RGB conversion profile. Even visually the colors are different. If, however, such a result should be, then the 16 points are 6% of the total gamut which is sufficient to adjust the green - I can't fathom wanting to change it more than that. And I can adjust B or R as well to compensate for the G. The point is that yes, there will be damage and loss without question but, at least for me, there are times when the benefits of being able to adjust in CMYK outweigh these damages. Maris - Original Message - From: "Karl Schulmeisters" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Saturday, May 26, 2001 3:51 PM Subject: Re: filmscanners: which space? | The complexity comes in when you add translation into another device. | | Lets say your original RGB values were 128,64,168, then after mapping | through CYMK and back to RGB you now have 138,16, 186 (I'm making these | numbers up, but they're somewhat believable. Now you want to print to a | printer that tends towards green and only takes RGB as input. So you print | a test print and low and behold its too green. You only have 16 levels of | green left to futz with. | | | From: "Maris V. Lidaka, Sr." <[EMAIL PROTECTED]> | To: <[EMAIL PROTECTED]> | Sent: Saturday, May 26, 2001 11:58 AM | Subject: Re: filmscanners: which space? | | | > Which is fine by me - so long as RxGxBx look the same as Rx'Gx'Bx' my | result | > will be what I want it to be. | > | > Maris | > | > - Original Message - | > From: "Karl Schulmeisters" <[EMAIL PROTECTED]> | > To: <[EMAIL PROTECTED]> | > Sent: Saturday, May 26, 2001 2:23 AM | > Subject: Re: filmscanners: which space? | > | > | > | That's not exactly the case. What is the case is that a particular Hue, | > | Intensity value - what our eyes perceive as a unique 'color value' can | be | > | rendered with multiple combinations of RGB. The same is not true for | CYMK | > | | > | So when you map from RGB into ANY color space, you essentially lose some | > | information. Namely you lose the mapping back to the original value | > | settings. That doesn't mean you can't get back to an RGB triplet that | > will | > | look the same, but it does mean that say if you had set the RGB triplet | > | value to Rx,Gy,Bz then mapped to CYMK and you went back, Rx',Gy',Bz' | might | > | not have | > | x=x',y=y',z=z'. | > | > [snipped] | > | | |
Re: filmscanners: which space?
CMYK is not a reduced color space compared to RGB. Printer CMYK is. But that is because the color space of the inks is more reduced. In essence, this isn't any different than manipulating The Zone System - ie where the dynamic range of paper is less than the dynamic range of film, which in turn is less than the dynamic range of our eyes. Maris Lidaka wrote: Sure, I completely agree. The key though, just like with the Zone System is to understand what is going on. - Original Message - From: <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Sunday, May 27, 2001 12:34 AM Subject: Re: filmscanners: which space? > > > Dear Karl > > As CMYK is a much reduced colour space compared to RGB I would have thought > that made it exactly the case. The true test would be to make multiple > conversions from RGB to CMYK and back and see if quality suffered, which of > course it does. > > The real test would be to make the conversion several times in different > programmes. > > R=25%, G=15%, B=10% converts to:- > > QUARK C25 M50 Y65 K64 > PAGEMAKER C56 M74 Y83 K65 > FREEHANDC75 M85 Y90 > PHOTOSHOP C41 M62 Y69 K70 > > It all depends on your standards. For LVT output you can't even make one CMYK > to RGB conversion without noticing adverse quality; for web use you can > probably get away with several. > > > > > In a message dated 26/5/01 8:29:01 am, [EMAIL PROTECTED] writes: > > << That's not exactly the case. What is the case is that a particular Hue, > > Intensity value - what our eyes perceive as a unique 'color value' can be > > rendered with multiple combinations of RGB. The same is not true for CYMK > > > So when you map from RGB into ANY color space, you essentially lose some > > information. Namely you lose the mapping back to the original value > > settings. That doesn't mean you can't get back to an RGB triplet that will > > look the same, but it does mean that say if you had set the RGB triplet > > value to Rx,Gy,Bz then mapped to CYMK and you went back, Rx',Gy',Bz' might > > not have > > x=x',y=y',z=z'. > > > This matters because you then can't just 'undo' any filtering you did prior > > to the mapping. Other color spaces have unique tuplet values. This has to > > do with the fact that in CYMK, intensity is mapped into the gray-scale K, > > whereas in RGB, intensity is a function of the particulare RGB values. >> > > > > Bob Croxford > Cornwall > England > > www.atmosphere.co.uk
Re: filmscanners: which space?
> CMYK is not a reduced color space compared to RGB. Printer CMYK is. But > that is because the color space of the inks is more reduced. OK. Are you suggesting that some sort of CMYK settings in Photoshop could make the CMYK mode's gamut more similar to RGB, and thus reduce the losses in RGB to CMYK to RGB conversions? (Asumming you would print to these CMYK settings.) Bob Wright Oops. That should have been ..."would not print to these CMYK settings..."
Re: filmscanners: which space?
- Original Message - From: Karl Schulmeisters <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Sunday, May 27, 2001 1:08 PM Subject: Re: filmscanners: which space? > CMYK is not a reduced color space compared to RGB. Printer CMYK is. But > that is because the color space of the inks is more reduced. OK. Are you suggesting that some sort of CMYK settings in Photoshop could make the CMYK mode's gamut more similar to RGB, and thus reduce the losses in RGB to CMYK to RGB conversions? (Asumming you would print to these CMYK settings.) Bob Wright
Re: filmscanners: which space?
I'm not a photoshop expert. I do know a bit about the abstract math behind the colorimetry. I don't see why you would not be able to do what you suggest. - Original Message - From: "Robert E. Wright" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Sunday, May 27, 2001 6:55 PM Subject: Re: filmscanners: which space? > > CMYK is not a reduced color space compared to RGB. Printer CMYK is. But > > that is because the color space of the inks is more reduced. > > OK. Are you suggesting that some sort of CMYK settings in Photoshop could > make the CMYK mode's gamut more similar to RGB, and thus reduce the losses > in RGB to CMYK to RGB conversions? (Asumming you would print to these CMYK > settings.) > > Bob Wright > Oops. That should have been ..."would not print to these CMYK settings..." >
Re: filmscanners: which space?
Consider this CMY are the complimentary colors of RGB. This means that according to color theory, you can mix any color in RGB that you would want to with CMY. The difference is that K is gray scale - intensity if you will. So what that means is that if you were to look at a plot of the color spaces with the X axis going 'into' the page, for RGB, you would see only one 'sheet' of color space. For CMYK you would see a 'sheet' corresponding to each gradation of 'K'. Clearly there is more gamut in CMYK. - Original Message - From: "Karl Schulmeisters" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Sunday, May 27, 2001 7:32 PM Subject: Re: filmscanners: which space? > I'm not a photoshop expert. I do know a bit about the abstract math behind > the colorimetry. I don't see why you would not be able to do what you > suggest. > - Original Message - > From: "Robert E. Wright" <[EMAIL PROTECTED]> > To: <[EMAIL PROTECTED]> > Sent: Sunday, May 27, 2001 6:55 PM > Subject: Re: filmscanners: which space? > > > > > CMYK is not a reduced color space compared to RGB. Printer CMYK is. > But > > > that is because the color space of the inks is more reduced. > > > > OK. Are you suggesting that some sort of CMYK settings in Photoshop could > > make the CMYK mode's gamut more similar to RGB, and thus reduce the losses > > in RGB to CMYK to RGB conversions? (Asumming you would print to these CMYK > > settings.) > > > > Bob Wright > > Oops. That should have been ..."would not print to these CMYK settings..." > > >
Re: filmscanners: which space?
Unfortunately there is one point which you don't mention - CMYK is defined as the color space or gamut of *printable* colors. In theory you could perhaps have more colors using C, M and Y with the addition of K but today's inks can't print all those colors and in fact can't print all the colors we can see on the monitor. When by definition CMYK is limited to printable colors, its gamut is smaller than that of RGB. CMYK is not defined mathematically but is defined using a device-dependent (i.e. the printing press) methodology. Maris - Original Message - From: "Karl Schulmeisters" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Sunday, May 27, 2001 11:55 PM Subject: Re: filmscanners: which space? | Consider this | | CMY are the complimentary colors of RGB. This means that according to color | theory, you can mix any color in RGB that you would want to with CMY. | The difference is that K is gray scale - intensity if you will. So what | that means is that if you were to look at a plot of the color spaces with | the X axis going 'into' the page, for RGB, you would see only one 'sheet' of | color space. For CMYK you would see a 'sheet' corresponding to each | gradation of 'K'. Clearly there is more gamut in CMYK. | | - Original Message - | From: "Karl Schulmeisters" <[EMAIL PROTECTED]> | To: <[EMAIL PROTECTED]> | Sent: Sunday, May 27, 2001 7:32 PM | Subject: Re: filmscanners: which space? | | | > I'm not a photoshop expert. I do know a bit about the abstract math | behind | > the colorimetry. I don't see why you would not be able to do what you | > suggest. | > - Original Message - | > From: "Robert E. Wright" <[EMAIL PROTECTED]> | > To: <[EMAIL PROTECTED]> | > Sent: Sunday, May 27, 2001 6:55 PM | > Subject: Re: filmscanners: which space? | > | > | > > > CMYK is not a reduced color space compared to RGB. Printer CMYK is. | > But | > > > that is because the color space of the inks is more reduced. | > > | > > OK. Are you suggesting that some sort of CMYK settings in Photoshop | could | > > make the CMYK mode's gamut more similar to RGB, and thus reduce the | losses | > > in RGB to CMYK to RGB conversions? (Asumming you would print to these | CMYK | > > settings.) | > > | > > Bob Wright | > > Oops. That should have been ..."would not print to these CMYK | settings..." | > > | > | | |
Re: filmscanners: which space?
Good point, I had forgot that. And this is in essence why in a given configuration, the CMYK space is more compressed than RGB. - Original Message - From: "Maris V. Lidaka, Sr." <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Sunday, May 27, 2001 11:48 PM Subject: Re: filmscanners: which space? > Unfortunately there is one point which you don't mention - CMYK is defined > as the color space or gamut of *printable* colors. In theory you could > perhaps have more colors using C, M and Y with the addition of K but today's > inks can't print all those colors and in fact can't print all the colors we > can see on the monitor. > > When by definition CMYK is limited to printable colors, its gamut is smaller > than that of RGB. CMYK is not defined mathematically but is defined using a > device-dependent (i.e. the printing press) methodology. > > Maris > > - Original Message - > From: "Karl Schulmeisters" <[EMAIL PROTECTED]> > To: <[EMAIL PROTECTED]> > Sent: Sunday, May 27, 2001 11:55 PM > Subject: Re: filmscanners: which space? > > > | Consider this > | > | CMY are the complimentary colors of RGB. This means that according to > color > | theory, you can mix any color in RGB that you would want to with CMY. > | The difference is that K is gray scale - intensity if you will. So what > | that means is that if you were to look at a plot of the color spaces with > | the X axis going 'into' the page, for RGB, you would see only one 'sheet' > of > | color space. For CMYK you would see a 'sheet' corresponding to each > | gradation of 'K'. Clearly there is more gamut in CMYK. > | > | - Original Message - > | From: "Karl Schulmeisters" <[EMAIL PROTECTED]> > | To: <[EMAIL PROTECTED]> > | Sent: Sunday, May 27, 2001 7:32 PM > | Subject: Re: filmscanners: which space? > | > | > | > I'm not a photoshop expert. I do know a bit about the abstract math > | behind > | > the colorimetry. I don't see why you would not be able to do what you > | > suggest. > | > - Original Message - > | > From: "Robert E. Wright" <[EMAIL PROTECTED]> > | > To: <[EMAIL PROTECTED]> > | > Sent: Sunday, May 27, 2001 6:55 PM > | > Subject: Re: filmscanners: which space? > | > > | > > | > > > CMYK is not a reduced color space compared to RGB. Printer CMYK is. > | > But > | > > > that is because the color space of the inks is more reduced. > | > > > | > > OK. Are you suggesting that some sort of CMYK settings in Photoshop > | could > | > > make the CMYK mode's gamut more similar to RGB, and thus reduce the > | losses > | > > in RGB to CMYK to RGB conversions? (Asumming you would print to these > | CMYK > | > > settings.) > | > > > | > > Bob Wright > | > > Oops. That should have been ..."would not print to these CMYK > | settings..." > | > > > | > > | > | > | >
