Mike Chaney's Tech Corner

Mike's Software => Qimage => Topic started by: wingspar on July 27, 2009, 11:34:23 PM



Title: Red Prints Orange
Post by: wingspar on July 27, 2009, 11:34:23 PM
I have recently purchased a new LaCie 324 LCD monitor, and have it calibrated with the LaCie Blue Eye Pro that came with the monitor.  I had a custom printer profile made right after I purchased the monitor.  Prints have been fine till last night.  I calibrated the monitor just before printing, and calibration numbers almost identical to last calibration.  Everything looked normal till the print came off the printer.  (Epson 2200).  The red jerseys came out orange.

I have gone thru all my settings in both printer driver and Qimage, and everything looks normal.  I am not double profiling.

The jerseys look red in every program I open, including Qimage.  After the prints came off the printer, I did a Soft Proof, and there the jerseys show up orange.  They show up red in the Qimage thumbnails, in the preview, in Nikon View, ViewNX, CS3 and ACR.  I’m stumped on this one.  I don’t feel I can send these to the customer.  I can’t begin to figure out what is happening.  Any ideas?


Title: Re: Red Prints Orange
Post by: Terry-M on July 28, 2009, 08:38:05 AM
It looks to me that the finger is pointing at the new profile.  :o
Is this a new paper or do you have another profile to try? Also, try another paper & profile, you probably only need to go as far as soft proofing from what you say.
Terry.


Title: Re: Red Prints Orange
Post by: Fred A on July 28, 2009, 09:29:59 AM
While reading your post, I immediately thought printer clogs, but when I finished, I have to agree with Terry.
Here's a simple test.
See attached snap.... open the color management box in Qimage, and check on the icon, dead center, right side. Hovering the mouse pointer shows a balloon that offers, Let Printer Manage color.
As you can see I already set that button and now the printer profile has changed to the correct one for that Let Printer manage color selection.
Also, please set your printer driver to ICM, not No Color Management.

Make a print.
It should be very close to perfect... if so that tells you that either your driver settings were off or your profile is off.
BTW, just to simplify, your monitor profile has no bearing on the print. Only if you used the image on the screen to radically change the colors of the image.
Otherwise, your monitor profile can be on or off and it makes no difference.
BTW 2   Please make a test print. That eliminates a lot of guessing. Soft proofing does use both printer profile and monitor profile.
Thanks

Fred


Title: Re: Red Prints Orange
Post by: wingspar on July 28, 2009, 04:17:30 PM
It looks to me that the finger is pointing at the new profile.  :o
Is this a new paper or do you have another profile to try? Also, try another paper & profile, you probably only need to go as far as soft proofing from what you say.

I haven’t had any problems with the new printer profile till now with these red jerseys.  This is not a new paper.  It’s Epson Premium Semi-gloss.  Pretty much the only paper I’ve used since I bought the 2200 back in 04 or 05.  See my reply to Fred on the Soft Proofing.

Here's a simple test.
See attached snap.... open the color management box in Qimage, and check on the icon, dead center, right side. Hovering the mouse pointer shows a balloon that offers, Let Printer Manage color.
As you can see I already set that button and now the printer profile has changed to the correct one for that Let Printer manage color selection.
Also, please set your printer driver to ICM, not No Color Management.

Make a print.
It should be very close to perfect... if so that tells you that either your driver settings were off or your profile is off.
BTW, just to simplify, your monitor profile has no bearing on the print. Only if you used the image on the screen to radically change the colors of the image.
Otherwise, your monitor profile can be on or off and it makes no difference.
BTW 2   Please make a test print. That eliminates a lot of guessing. Soft proofing does use both printer profile and monitor profile.

Well, I don’t understand the rational behind your screen shot, but I tried it.  Soft Proofing in Qimage looked fine, so I went ahead and printed.  Prints came out dark with a heavy green tint to them.  Things just went from bad to worse.


Title: Re: Red Prints Orange
Post by: UltraChrome on July 28, 2009, 04:42:38 PM
I'm confused! In your first post, you say "Everything looked normal till the print came off the printer.  (Epson 2200).  The red jerseys came out orange." This would indicate that the monitor was correct and the prints were wrong.

Then you say, in the same post, "The jerseys look red in every program I open, including Qimage.  After the prints came off the printer, I did a Soft Proof, and there the jerseys show up orange.  They show up red in the Qimage thumbnails, in the preview, in Nikon View, ViewNX, CS3 and ACR." This would indicate the monitor is now wrong as well as the print.

Then you say you tried Fred's solution and the prints came out green but the monitor soft proof looked OK. Am I correct so far?

If so, there are at least two possible problems. I would look first at the profile. You don't state why you installed a "custom printing profile" but since you are using Epson paper, just download their standard profile and see if anything improves. If not, I would look at an inking problem, such as a clogged nozzle or two.

If neither works, try printing out of one of your other programs and see what happens. That would help isolate where the problem is. I'm suspecting your 2200 driver settings and/or profile...


Title: Re: Red Prints Orange
Post by: Terry-M on July 28, 2009, 04:53:09 PM
Fred said
Quote
While reading your post, I immediately thought printer clogs
and
Quote
Let Printer Manage color.
This suggestion will always give a reasonable result.

There seems to be a great deal of inconsistency, blocked nozzles need to be eliminated from the equation, so I suggest a check & clean.
Terry.


Title: Re: Red Prints Orange
Post by: wingspar on July 28, 2009, 05:14:50 PM
Then you say you tried Fred's solution and the prints came out green but the monitor soft proof looked OK. Am I correct so far?

Yes.

Quote
If so, there are at least two possible problems. I would look first at the profile. You don't state why you installed a "custom printing profile" but since you are using Epson paper, just download their standard profile and see if anything improves. If not, I would look at an inking problem, such as a clogged nozzle or two.

If neither works, try printing out of one of your other programs and see what happens. That would help isolate where the problem is. I'm suspecting your 2200 driver settings and/or profile...

I purchased a custom profile because the canned Epson profiles gave a green tint to all of my prints, which I was able to fix manually before printing, as it was consistent.  The custom profile put an end to that, except for these red jerseys I’m trying to print.

There seems to be a great deal of inconsistency, blocked nozzles need to be eliminated from the equation, so I suggest a check & clean.

Checking for clogged nozzles with the 2200 is automatic before printing.  There are no clogged nozzles.


Title: Re: Red Prints Orange
Post by: Fred A on July 28, 2009, 07:33:16 PM
Quote
checking for clogged nozzles with the 2200 is automatic before printing.  There are no clogged nozzles
Sorry,
I had been on chore duty.
Wow what a lot of information and mis-information.
I have seen/used a few 2200s and I never knew they do auto nozzle cleaning. You would go through ink like **** through a goose.
Please do a nozzle clean/head clean.
If you got worse prints (and green instead of red) using the generic profile I suggested that you use,
1) you either have the driver settings set incorrectly, (should have been ICM), or you have clogged nozzles.
2) If you needed to get a custom profile to override the EPSON premade profile designed for their own paper, that doesn't sit well either.
3) Can you please tell us the name of the profile that you used from Epson; filename and descriptor name.
That would solve a lot too.

Trying to help!
Fred


Title: Re: Red Prints Orange
Post by: Terry-M on July 28, 2009, 07:49:38 PM
Quote
Can you please tell us the name of the profile that you used from Epson; filename and descriptor name.
That would solve a lot too.
One more question too, are you using Epson Inks, sounds obvious but trying to cover everything  ;)
Terry.


Title: Re: Red Prints Orange
Post by: UltraChrome on July 28, 2009, 08:06:29 PM
Another basic question: what driver version are you using and with what operating system? Thanks - we all wanna help  ;D   As a matter of general information, the green and/or reddish casts you mention are usually caused when the Epson driver is NOT set to "no color adjustment" (in the "advanced" section of the driver), which is where they need to be for any software to control the final print color.

Edit addition: you also need to select the proper paper in your Epson driver, even though you are not using it for your color control. The driver determines the ink flow.


Title: Re: Red Prints Orange
Post by: Fred A on July 28, 2009, 08:31:26 PM
I just downloaded the Epson profiles on your behalf for the semi gloss paper.
There were two.
One is for the 1440 dpi setting and the other for the 2880 dpi setting.
Regardless, it should be one of those two lower ones.
The driver gets set to NO COLOR ADJUSTMENT.

See the attached screen snap.

What was the name of the driver you used, and then discarded as no good? I am really anxious to hear the answer to what ink you use.

Fred


Title: Re: Red Prints Orange
Post by: wingspar on July 29, 2009, 03:02:26 AM
I have seen/used a few 2200s and I never knew they do auto nozzle cleaning. You would go through ink like **** through a goose.
Please do a nozzle clean/head clean.
If you got worse prints (and green instead of red) using the generic profile I suggested that you use,
1) you either have the driver settings set incorrectly, (should have been ICM), or you have clogged nozzles.
2) If you needed to get a custom profile to override the EPSON premade profile designed for their own paper, that doesn't sit well either.
3) Can you please tell us the name of the profile that you used from Epson; filename and descriptor name.

It is automatic that I do a nozzle check before sending prints to the 2200.  If the printer did that automatically, it would drive me nuts.  Didn’t expect anyone to read that into my post.  I do Not have clogged nozzles. 

Driver always set to ICM and no color management.

It is quite common to have custom printer profiles made, as the generic ones from Epson are ok, but not as good as custom profiles.  The Epson profile I used for years is SP2200Prem.Semigloss 1440.icc

I am currently using a custom profile made by Cathy’s Profiles, which has removed all printing headaches, until this red jersey printing orange problem.

One more question too, are you using Epson Inks, sounds obvious but trying to cover everything

I use only Epson inks.  Never used anything else.  Don’t intend to.

Another basic question: what driver version are you using and with what operating system? Thanks - we all wanna help  ;D   As a matter of general information, the green and/or reddish casts you mention are usually caused when the Epson driver is NOT set to "no color adjustment" (in the "advanced" section of the driver), which is where they need to be for any software to control the final print color.

Edit addition: you also need to select the proper paper in your Epson driver, even though you are not using it for your color control. The driver determines the ink flow.

Using latest Driver from Epson, and it’s several years old.  Too tired to look it up.  It is set to ICM, No Color Adjustment, and the proper paper is selected.  I’ve had the 2200 and Qimage for several years.  I certainly know the basics.


Title: Re: Red Prints Orange
Post by: wingspar on July 29, 2009, 03:05:24 AM
What was the name of the driver you used, and then discarded as no good?

I’m unaware of discarding a driver.   ???   ???


Title: Re: Red Prints Orange
Post by: Fred A on July 29, 2009, 09:39:11 AM
Sorry, Gary...
I meant what profile did you discard and replace with a custom profile.

If the setup I gave you using the \pRGB.icm profile and setting the driver to ICM produced unacceptable green prints, then I have to say printer problem; of some nature.
Have you printed from some other program? Do you get skewed results or excellent results?

Kathy makes wonderful profiles, so no argument there. That points yet another finger at the printer.

Fred



Title: Re: Red Prints Orange
Post by: UltraChrome on July 29, 2009, 12:54:01 PM
re: "Using latest Driver from Epson, and it’s several years old.  Too tired to look it up.  It is set to ICM, No Color Adjustment, and the proper paper is selected.  I’ve had the 2200 and Qimage for several years.  I certainly know the basics."

I don't believe you can select both "ICM" and "No Color Management" at the same time. Select ONLY "No Color Management".

You also may have a corrupted driver. It might be worth the time to remove the driver and reinstall the latest version on the Epson site for your OS. Just do a search on "2200" and select the first item it brings up.


Title: Re: Red Prints Orange
Post by: Terry-M on July 29, 2009, 01:11:15 PM
Quote
I don't believe you can select both "ICM" and "No Color Management" at the same time. Select ONLY "No Color Management"
In Epson driver's it is ICM and then NCA, see attached.
Terry.


Title: Re: Red Prints Orange
Post by: wingspar on July 29, 2009, 04:43:00 PM
Sorry, Gary...
I meant what profile did you discard and replace with a custom profile.

If the setup I gave you using the \pRGB.icm profile and setting the driver to ICM produced unacceptable green prints, then I have to say printer problem; of some nature.
Have you printed from some other program? Do you get skewed results or excellent results?

Kathy makes wonderful profiles, so no argument there. That points yet another finger at the printer.

I figured that’s what you meant.  I was going to make a crack about how good of a driver my significant other is, and that I’ will keep her around for years to come, but decided against it.  ;D  It is the SP2200Prem.Semigloss 1440.icc profile I mentioned in reply #11.  I didn’t discard it, just not using it since getting the custom profile made.

I’ve tried printing from Photoshop with the same results.  I supposed it’s possible I could have messed up somewhere else when I tried the \pRGB.icm profile and got green prints.  If the printer is part of the problem, how would I go about troubleshooting that?  The printer is at least 5 years old, but may sit for long periods of time without being used.  I have no idea how many prints I’ve made over the years.


Title: Re: Red Prints Orange
Post by: wingspar on July 29, 2009, 04:46:00 PM
In Epson driver's it is ICM and then NCA, see attached.
Terry.

That is exactly how I have always had the driver set up.


Title: Re: Red Prints Orange
Post by: Fred A on July 29, 2009, 05:02:38 PM

I’ve tried printing from Photoshop with the same results.  I supposed it’s possible I could have messed up somewhere else when I tried the \pRGB.icm profile and got green prints.  If the printer is part of the problem, how would I go about troubleshooting that?  The printer is at least 5 years old, but may sit for long periods of time without being used.  I have no idea how many prints I’ve made over the years.

Gary, you said it all in this post.
Sometimes, the best way to get a bandaid off of your hairy arm, is a quick yank/rip.
It is time!
We will each send condolence emails on your loss of the 2200, but it is time!
Investigate an R1900 or some other suitable replacement, and just remember your old friend 2200 and the good times.

Fred


Title: Re: Red Prints Orange
Post by: wingspar on July 29, 2009, 05:18:44 PM
Gary, you said it all in this post.
Sometimes, the best way to get a bandaid off of your hairy arm, is a quick yank/rip.
It is time!
We will each send condolence emails on your loss of the 2200, but it is time!
Investigate an R1900 or some other suitable replacement, and just remember your old friend 2200 and the good times.

I did a tiny bit of research on printers a couple of months ago.  First time I’d even heard of the 2880, which would probably be my first choice should I replace the 2200.  I read up on the R1900, and that also looks like a good choice, specially for B&W, but I think I’ve printed 3 or 4 B&W prints over the years, so good B&W prints are nice, they aren’t critical for me.  There are so many variables when printing B&W.  Even a simple thing as a different paper can change the entire look of a B&W print.  Of course, the 3800 looks very nice, but I’d have to knock out a wall to build a place to put it.  As is, the 2200 rocks my table and monitor.

To be honest, I’m not really sure if this is a printer problem, or an out of gamut red on this print, or a combination of both.  I’d like to do a little more experimenting before deciding to replace the printer, but unfortunately, I’ve fallen down in my paper supply, and don’t have the paper to experiment with, but will have plenty when it gets delivered in a couple of days.  I’ve never let my paper supply fall like this.

Could it be a faulty ink cartridge that might be contributing to the orange/red problem?  The nozzle check prints perfectly.


Title: Re: Red Prints Orange
Post by: UltraChrome on July 29, 2009, 05:45:56 PM
Sorry for my mis-information on the driver. I was working from memory so I went back and uploaded the driver (verson 5.50 for XP). I do see that you can and should select !CM and No Color Management. My bad!

You might want to take the file and have it printed elsewhere (a friend? a drugstore?) to see if it is correct. If none of your programs are printing it correctly that would at least eliminate the file as a suspect. Are other prints still correct?

If you decide to go new, I'd highly recommend trying to fit the 3800. I've had mine since they were introduced (it replaced my 2200) and it has done nothing but print extrodinary images (more than 4500 at present) since I bought it. The 2880 is also a nice machine based on what I have read.



Title: Re: Red Prints Orange
Post by: Seth on July 31, 2009, 06:56:39 PM
Gary-

Download one of the color test charts.  One that just has CYMRGB graduated bars and print the full sheet out of PS or QI.  If those colors are okay, so is your printer.

If it's faster, I can e-mail one to you.


Title: Re: Red Prints Orange
Post by: wingspar on August 01, 2009, 01:27:46 AM
Ok.  An update.  I was too low on paper to do any more experimenting, and just got a delivery of paper today.  I posted this same question at FM, and that thread went off in another direction, but in the process, I learned some valuable things about Photoshop.  The reds were seriously over saturated, and some of them were out of gamut.  I fixed this by reducing the saturation, and now the jersey prints red.  Not perfect, but no longer orange.  I will say that the soft proof in Qimage still seems to show the red a tad bit towards orange, and not as red as the print came out, but quite close.  I seemed to create the problem by over saturating the reds in an effort to obtain a striking print.   The printer driver/profile was not capable of showing this, hence, my prints coming out orange.  I think a new printer just got shoved back down the priority list for the second time in the last 3 months.   :'(

If you decide to go new, I'd highly recommend trying to fit the 3800. I've had mine since they were introduced (it replaced my 2200) and it has done nothing but print extrodinary images (more than 4500 at present) since I bought it. The 2880 is also a nice machine based on what I have read.

The 3800 sounds very nice, and very tempting.  I saw one in person a couple of months ago, and took measurements.  I have no place to put one at all.  If I was to replace the 2200, my first choice would probably be a 2880.  It took a lot of work to fit the 2200 in here, and the 2880 would fit right in without any further construction/removal of walls.  I have no walls I can remove.  As I look around, I suppose there is a way to build a platform for a 3800 to sit on, but what a job that would be, and I also have to wonder how long you can make a USB cable work with the 3800?  I’d probably need about a 20 to 25-foot long cable.

Gary-

Download one of the color test charts.  One that just has CYMRGB graduated bars and print the full sheet out of PS or QI.  If those colors are okay, so is your printer.

If it's faster, I can e-mail one to you.

Where can one fine a color test chart?  I just upgraded from a 728kps DSL connection to a 5mb cable connection, so download speeds are fine.


Title: Re: Red Prints Orange
Post by: Terry-M on August 01, 2009, 06:56:56 AM
Gary, you started this thread by saying
Quote
I have recently purchased a new LaCie 324 LCD monitor,
also
Quote
The printer driver/profile was not capable of showing this,
Your new monitor probably has a much wider gamut that your printer, look at the image on the thread here http://ddisoftware.com/tech/computer-software/colour-gamut-visualisation/
I wondered what rendering intent you were using, changing that may help a little.
Terry.


Title: Re: Red Prints Orange
Post by: wingspar on August 01, 2009, 05:57:08 PM
Your new monitor probably has a much wider gamut that your printer, look at the image on the thread here http://ddisoftware.com/tech/computer-software/colour-gamut-visualisation/

I saw that thread, but it was a little too technical for me, or at least, it is something I’ll have to look at more closely when I am in the correct frame of mind to digest some of the info.  Gamut is just a word that I don’t really understand, but now I see I need to learn a tad bit more about it.

You are most likely correct in that my monitor is capable of displaying a much wider gamut of colors than my printer is.  It’s cool for processing for the web, but I have to watch it when processing for printing.

One thing I learned this morning from the thread at FM was to try a different “Printer Profile Rendering Intent” in Qimage.  The default in Qimage is Perceptual, and it is all I’ve ever used.   It was suggested I try using Relative Colorimetric for this print.  After making my changes to eliminate all out of gamut areas of the image, and even reduce the saturation a tad, I made a print using Perceptual, and one using Relative Colorimetric.  The difference in the red showed up in the soft proof, and in the print between Perceptual, and Relative Colorimetric.  I got much better reds printing with Relative Colorimetric.

I have now fixed the red in the jerseys and in the process learned a lot about gamut and Photoshop, and even something about Qimage, and even a little bit about my monitor, which I already knew, but now make sense of it, and sinks the knowledge into a permanent crease in my brain.

I also downloaded a Printer Test File (top left of page) http://www.digitaldog.net/tips/ and the colors printed perfect.   :)


Title: Re: Red Prints Orange
Post by: Seth on August 01, 2009, 07:11:30 PM
... try a different “Printer Profile Rendering Intent” in Qimage.  The default in Qimage is Perceptual, and it is all I’ve ever used.   It was suggested I try using Relative Colorimetric for this print...  I got much better reds printing with Relative Colorimetric....

I went to Relative permanently in PS and QI.  They say it's for critical colors.  Most of mine are.  Welllllllllllll, not that critical, but I like them right.

I just went through the "red" ting with NASCAR.  Always do with that and IRL drivers in red.  They either have magenta in the mid-tones or go orange.  I know it's from using auto white balance and having so much of one color in the pic, but it's fixable.  That's where Selective Color and the History Brush come in.  Especially when the unifrms through the red cast (or geen, etc.) into the faces.

BTW- Also, I quit soft-proofing.  There is just NO way an illuminated monitor can truly reproduced a reflective paper surface, IMO.  I just got to the point that I know that to reproduce what I see (profiles aside) on--for example, Double-Sided Matte--I have to have QI do a +3 Contrast, +4 Gamma and +2 Blue.  So I have a saved attachment called DSM fix.

What the heck, it works.


Title: Re: Red Prints Orange
Post by: Terry-M on August 01, 2009, 07:55:55 PM
Quote
I went to Relative permanently in PS and QI.  They say it's for critical colors.  Most of mine are.  Welllllllllllll, not that critical, but I like them right.
But if the colour is out of gamut wrt the printer/paper/ink combination, then it can never be "right", how it is converted is a compromise.
I have found the following diagrams helpful. (With acknowledgement to the Colour Collective, Warwick UK)
"A" is an out-of-gamut colour; "B" is within gamut.
Perceptual: Scales large colour space into small. All colours are changed. Maintains balance of image.
(http://www.pbase.com/tjm04/image/115601786/medium.jpg)

Colorimetric Rendering: In gamut colours not changed. Out of gamut colours clipped to nearest. Balance of image lost. Relative Colorimetric adapts for differences in whitepoint.
(http://www.pbase.com/tjm04/image/115601791/medium.jpg)

Terry.
PS. the full set of CM guides can be downloaded here:
http://www.nativedigital.co.uk/shop/page.php/1ada23af7c69cf163b079c8a6325a004?xPage=support_general_cm.html


Title: Re: Red Prints Orange
Post by: Seth on August 01, 2009, 08:35:21 PM
Hi Terry-

Although I started it, I don't like hijacking threads.  I started a new one on this at http://ddisoftware.com/tech/qimage/gamut-and-color-space/ (http://ddisoftware.com/tech/qimage/gamut-and-color-space/).

I don't know if you want to drag your post above over there.


Title: Re: Red Prints Orange
Post by: Terry-M on August 01, 2009, 08:44:04 PM
Quote
I don't know if you want to drag your post above over there
I'm sure how to do that  ???
I think it's ok. here, hopefully it's of some help to Gary (wingspar) and you've put in a link  :)
Terry.


Title: Re: Red Prints Orange
Post by: wingspar on August 02, 2009, 05:20:51 PM
I went to Relative permanently in PS and QI.  They say it's for critical colors.  Most of mine are.  Welllllllllllll, not that critical, but I like them right.

I posted a question for Mike on that very subject in your gamut-and-color-space thread.  It made me wonder why Perceptual is the default in Qimage.

Quote
BTW- Also, I quit soft-proofing.  There is just NO way an illuminated monitor can truly reproduced a reflective paper surface, IMO.  I just got to the point that I know that to reproduce what I see (profiles aside) on--for example, Double-Sided Matte--I have to have QI do a +3 Contrast, +4 Gamma and +2 Blue.  So I have a saved attachment called DSM fix.

What the heck, it works.

Soft proofing in Qimage is still a valuable tool to me, even tho an illuminated monitor will never match exactly the reflective surface of a print, soft proofing can still give you a good picture on how your colors will print, such in my “Red prints Orange” thread.  When I started that thread, the image on the monitor looked good, it looked good in the preview before printing, but Soft Proof in Qimage made them look orange, and they printed orange.  Now after all I’ve learned on gamut and out of gamut colors, I’ve got the image so that it soft proofs red, and prints red even tho the Soft Proof on the screen looks washed out in comparison to the print, I can still tell that it is now red, and will print red.  So I still see Soft Proofing in Qimage as a valuable tool.


Title: Re: Red Prints Orange
Post by: wingspar on August 02, 2009, 05:32:01 PM
I have found the following diagrams helpful. (With acknowledgement to the Colour Collective, Warwick UK)

To be honest, I have stared at those two diagrams a lot, both last night, and again this morning, and the only difference I can see is that the “B” does not have an arrow next to it in the second image.  What am I missing?


Title: Re: Red Prints Orange
Post by: Terry-M on August 02, 2009, 07:50:04 PM
Quote
To be honest, I have stared at those two diagrams a lot, both last night, and again this morning, and the only difference I can see is that the “B” does not have an arrow next to it in the second image.  What am I missing?
Sorry, I didn't mean to keep you up all night  ;D  :-[
The arrows are meant to show the change in one particular colour as it is converted. With RC, a colour outside the gamut moves to the edge of the gamut (de-saturated in effect) and a colour in gamut stays the same. With Perceptual, all colours change, compressed into the gamut, rather like compressing a soft ball into a smaller size.
I hope that has not confused you more. If it has, I hope someone else (like expert Mike maybe) can explain it more clearly.
I've been slowly learning about CM over the last 4 or 5  years, it's a long learning curve  :(
Terry.


Title: Re: Red Prints Orange
Post by: wingspar on August 03, 2009, 05:23:04 PM
I do understand what the diagrams are supposed to show, it’s that neither of us can see it.  That’s why I said the only difference I can see is that the arrow is gone from the “B” in the second diagram.  Any other difference is too subtle for either of us to see it.