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Calibration software for an iMAC
David Kilpatrick wrote:
wrote: I have an iMAC about a year old. I am trying to calibrate the monitor to assist in making photos. I have used the Spyder3 software and colorimeter in the process. The problem is that the prints all come out noticeably darker than the image on the screen. The Spyder people say this is Apple's fault. The brightness control (really the backlighting control) on the display will not sufficiently reduce the brightness to get an accurate calibration. The only work around I see is to reduce the brightness in Photoshop below what looked good on the screen and hope the printer responds by yielding a print of the correct brightness. But this adjustment is completely ad hoc and is just the kind of fiddling I hoped to avoid using the calibration routines. Two questions: 1) Does anybody have a better way to use Spyder3 to compensate for this problem? 2) If not, what alternative calibration system might be used that will avoid (or at least mitigate) this problem? I read good things about the Macbeth systems, but will they run into the same problem? Thanks for the help. First ignore all the garbage in troll replies - the iMac 24 inch screen, matt, if that's what you have, is one of the best for colour accuracy and actually doesn't need calibrating at all. I have a Spyder 2 Pro, a ColorMunki and a Huey Pro. Guess how I calibrat? I use Apple's excellent visual utility in Advanced mode, making sure I do the following: Set the monitor to minimum brightness (not excessive, and very comfortable in my office with normal lighting, or with my window shutters part open on a sunny day like this). Calibrate following Apple's sequence, being sure to sit around two feet from the monitor, and being sure to blur your eyes slightly and avoid using the central foveal zone of the eye (do not look at or focus on the target when adjusting - defocus by looking 'through' the target, and look an inch to the side of the matching patch). This will ensure that visual accommodation does not screw up your ability to spot when the density/colour matches. Finally, performing the profile creation Native Gamma and Native White Point. Don't adjust these to 1.8 or 2.2, or 6500 or D65 or 5000 or whatever. The monitor is already fairly close to a gamma between Mac (1.8) and PC (2.2) and very closely to a D65 whitepoint. Never, ever use a 5000/D50 white point as this is an old standard which will make the screen look murky and yellow. Save/apply the resulting profile. It will have fewer tone breaks or unwanted colour shifts than a Spyder 3 profile, because the contrast scale of the monitor and its WP have not been messed with. Calibrators can never add accuracy - they can only approximate it by REDUCING the range of the monitor; any change they make to levels in one channel or brightness zone will be reflected in a loss of bit depth elsewhere in the tone scale. The Apple manual/visual calibration method loses less bit depth than most hardware calibrators. After having done this, ensure your printer driver settings and paper profiles all work correctly. I have a laser printer, the second I've had, and no matter what I do - always darker, always poor colour. I also have an Epson 3800 and the colour is a perfect match for the screen without the slightest effort. "Perfect match"? Really David, I expect more accuracy from you. There is no way a transparent (monitor) will match a reflective (paper). Having said all the above. Unless one 'simulates' the paper while in (eg) Photoshop, then what you see on the screen is never going to match what prints. And it is that fateful step of simulating the paper as I described in my other post that gets you there. I too have an iMac 24 an Epson 3800, and as closely as I have calibrated it (very minor change from the apple visual calibration), unless one views the photoshop image with 'simulate paper' on, one will not have anything close to the print. Cheers, Alan -- -- r.p.e.35mm user resource: http://www.aliasimages.com/rpe35mmur.htm -- r.p.d.slr-systems: http://www.aliasimages.com/rpdslrsysur.htm -- [SI] gallery & rulz: http://www.pbase.com/shootin -- e-meil: Remove FreeLunch. -- usenet posts from gmail.com and googlemail.com are filtered out. |
#3
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Calibration software for an iMAC
In article , David Kilpatrick
wrote: First ignore all the garbage in troll replies - the iMac 24 inch screen, matt, if that's what you have, is one of the best for colour accuracy and actually doesn't need calibrating at all. I have a Spyder 2 Pro, a ColorMunki and a Huey Pro. Guess how I calibrat? I use Apple's excellent visual utility in Advanced mode, making sure I do the following: although it's an excellent screen, there are better, although much more expensive. while the calibration is pretty good out of the box, it helps to profile it (many people don't understand the difference). Set the monitor to minimum brightness (not excessive, and very comfortable in my office with normal lighting, or with my window shutters part open on a sunny day like this). Calibrate following Apple's sequence, being sure to sit around two feet from the monitor, and being sure to blur your eyes slightly and avoid using the central foveal zone of the eye (do not look at or focus on the target when adjusting - defocus by looking 'through' the target, and look an inch to the side of the matching patch). if it doesn't need calibrating as you say, why are you calibrating it? furthermore, calibrating by eye is at best, slightly better than doing nothing at all, and often much worse. using a hardware calibration puck is *much* better because it eliminates the huge variability of the eye. This will ensure that visual accommodation does not screw up your ability to spot when the density/colour matches. exactly why a hardware device is better. Finally, performing the profile creation Native Gamma and Native White Point. Don't adjust these to 1.8 or 2.2, or 6500 or D65 or 5000 or whatever. The monitor is already fairly close to a gamma between Mac (1.8) and PC (2.2) and very closely to a D65 whitepoint. Never, ever use a 5000/D50 white point as this is an old standard which will make the screen look murky and yellow. Save/apply the resulting profile. It will have fewer tone breaks or unwanted colour shifts than a Spyder 3 profile, because the contrast scale of the monitor and its WP have not been messed with. Calibrators can never add accuracy - they can only approximate it by REDUCING the range of the monitor; any change they make to levels in one channel or brightness zone will be reflected in a loss of bit depth elsewhere in the tone scale. The Apple manual/visual calibration method loses less bit depth than most hardware calibrators. nonsense. a profile from a spyder or other device will be *much* better than one done by eye. |
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Calibration software for an iMAC
Alan Browne wrote:
I too have an iMac 24 an Epson 3800, and as closely as I have calibrated it (very minor change from the apple visual calibration), unless one views the photoshop image with 'simulate paper' on, one will not have anything close to the print. Have you got a viewing light? If you use a viewing light which provides about the same reflected brightness as the apparent brightness of the monitor, the match can very close. Of course, I am used to viewing proofs and prints, and monitors. I've been doing it since the first colour monitors appeared (we had the first Radius with calibration and also one of the very early Barcos which I never liked much). I do not expect a 'match' in the unrealistic sense some users may. Also, I'm not messing with out of gamut colour adjustments and to some photographers my pix must look very plain. It was maybe three years ago I did a talk for Hawick Camera Club, and at the end of the evening, they asked for some quick help with printing problems. They had a stack of very bad prints. It took me about twenty minutes - not being familiar with Windows 2000 which I think was the system - to find the Adobe Gamma utility, set Photoshop colour prefs properly, load an image, implement and note down the correct driver settings (for their future use) and get a print out which almost raised a cheer - it matched the screen! At that stage none of the users of their new digital photo system understood how all the components in a CMM work, or how the printer driver (it was an Epson, not sure which one) worked. I think everyone is better informed now but I still deal with a lot of calls helping readers get this stuff right. http://www.pbase.com/davidkilpatrick/image/110547036 Here's a shot of the Grafilite with a print and a monitor image - in order to get the scales right, I used a small old monitor, Apple 15 studio, which actually gives crazy shifts in contrast with vertical view angle and of course the print is seen with sheen from the gloss in the photo. In real life the 'lit' print can be a very neat match to the screen placed near it, especially with my iMac 24 on minimum brightness at native WP. David |
#5
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Calibration software for an iMAC
nospam wrote:
if it doesn't need calibrating as you say, why are you calibrating it? To create a profile - as you suggest. In fact any of the visual adjustments made on this screen are so small they may not be worth making. There is a very small difference between the default profile and the one created by the Apple utility, but there's a big difference if I use a hardware calibrator - and generally, the results are worse. It would be more accurate to describe my approach as profiling the monitor, rather than calibrating it. Calibrating is what we used to do with hardware adjustment of the guns in CRTs or loading new LUTs into display cards. exactly why a hardware device is better. Far from true. Hardware devices vary greatly and so does the software. I've tested dozens of them. Some are disatrous (the Pantone Huey is a good example - next to useless, especially on most laptops for which it is a natural companion). nonsense. a profile from a spyder or other device will be *much* better than one done by eye. Most of the calibration problems I have had brought to me by professionals have been caused by hardware devices. When I use a hardware device (or test one) I will use the recommended procedures which often involve changes in brightness, match to specific gamma, match to WP. It is very common to find - especially with 6-bit depth LCD screens and laptops generally - that these adjustments create tone breaks including banding in sky gradations. Brightness may also be reduced to the point that the display becomes unusable. I'll also use my own standards, which involve working to a reasonable brightness, using native WP and gamma. In theory, the hardware device should then create a profile which corrects only for non-linearity of the RGB curves of the monitor. Some are better than others. The extreme 20-minute profiling sequence of the highest end software for the Spyder 2 Pro (I had three or four different programs for it) never produced results I liked. The simple Colormunki approach of reading just eight levels per colour, very quickly, seems just as good in terms of final profile. Even so, I use the visual/manual profile creation method. It produces a better profile. I get stacks of RGB black and white images from my professional readers (mono accounts for 70 per cent of all UK social photography at awards/exhibition level) and with my profiles, they all look just as they should with no tint shifts at any density. That is unless the photographer has used a hardware calibrator, ended up with a tint shift in the shadows, then messed around in Photoshop trying to remove it and ended up with a red or green bias showing up in gradations. A good test of whether your monitor is correctly calibrated is simply to take any Photoshop RGB image, execute the Desaturate command, and view it. If there is absolutely no hint of any tint shift at any density, your monitor is fine and just needs a profile, not a calibration+profile. David |
#6
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Calibration software for an iMAC
David Kilpatrick wrote:
Alan Browne wrote: I too have an iMac 24 an Epson 3800, and as closely as I have calibrated it (very minor change from the apple visual calibration), unless one views the photoshop image with 'simulate paper' on, one will not have anything close to the print. Have you got a viewing light? If you use a viewing light which provides about the same reflected brightness as the apparent brightness of the monitor, the match can very close. No. After printing I typically walk them into my dining room as it has a mix of south east light and incandescent lighting. But glad to see you've changed to "match can be very close". Of course, I am used to viewing proofs and prints, and monitors. I've been doing it since the first colour monitors appeared (we had the first Radius with calibration and also one of the very early Barcos which I never liked much). I do not expect a 'match' in the unrealistic sense some users may. Also, I'm not messing with out of gamut colour adjustments and to some photographers my pix must look very plain. Then you must have been aloof or lazy when you wrote: "the colour is a perfect match for the screen without the slightest effort." as that is simply not possible. It was maybe three years ago I did a talk for Hawick Camera Club, and at the end of the evening, they asked for some quick help with printing problems. They had a stack of very bad prints. It took me about twenty minutes - not being familiar with Windows 2000 which I think was the system - to find the Adobe Gamma utility, set Photoshop colour prefs properly, load an image, implement and note down the correct driver settings (for their future use) and get a print out which almost raised a cheer - it matched the screen! At that stage none of the users of their new digital photo system understood how all the components in a CMM work, or how the printer driver (it was an Epson, not sure which one) worked. I think everyone is better informed now but I still deal with a lot of calls helping readers get this stuff right. http://www.pbase.com/davidkilpatrick/image/110547036 Here's a shot of the Grafilite with a print and a monitor image - in order to get the scales right, I used a small old monitor, Apple 15 studio, which actually gives crazy shifts in contrast with vertical view angle and of course the print is seen with sheen from the gloss in the photo. In real life the 'lit' print can be a very neat match to the screen placed near it, especially with my iMac 24 on minimum brightness at native WP. Well, that image as you present it above is the least convincing ... It took me several weeks to get the Epson 3800, my iMac and CS3 to play together properly - which is not an exact match. And that is limited to a few papers to date. -- -- r.p.e.35mm user resource: http://www.aliasimages.com/rpe35mmur.htm -- r.p.d.slr-systems: http://www.aliasimages.com/rpdslrsysur.htm -- [SI] gallery & rulz: http://www.pbase.com/shootin -- e-meil: Remove FreeLunch. -- usenet posts from gmail.com and googlemail.com are filtered out. |
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Calibration software for an iMAC
David Kilpatrick wrote:
nospam wrote: if it doesn't need calibrating as you say, why are you calibrating it? To create a profile - as you suggest. In fact any of the visual adjustments made on this screen are so small they may not be worth making. There is a very small difference between the default profile and the one created by the Apple utility, but there's a big difference if I use a hardware calibrator - and generally, the results are worse. It would be more accurate to describe my approach as profiling the monitor, rather than calibrating it. Calibrating is what we used to do with hardware adjustment of the guns in CRTs or loading new LUTs into display cards. exactly why a hardware device is better. Far from true. Hardware devices vary greatly and so does the software. I've tested dozens of them. Some are disatrous (the Pantone Huey is a good example - next to useless, especially on most laptops for which it is a natural companion). nonsense. a profile from a spyder or other device will be *much* better than one done by eye. Most of the calibration problems I have had brought to me by professionals have been caused by hardware devices. When I use a hardware device (or test one) I will use the recommended procedures which often involve changes in brightness, match to specific gamma, match to WP. It is very common to find - especially with 6-bit depth LCD screens and laptops generally - that these adjustments create tone breaks including banding in sky gradations. Brightness may also be reduced to the point that the display becomes unusable. I'll also use my own standards, which involve working to a reasonable brightness, using native WP and gamma. In theory, the hardware device should then create a profile which corrects only for non-linearity of the RGB curves of the monitor. Some are better than others. The extreme 20-minute profiling sequence of the highest end software for the Spyder 2 Pro (I had three or four different programs for it) never produced results I liked. The simple Colormunki approach of reading just eight levels per colour, very quickly, seems just as good in terms of final profile. Even so, I use the visual/manual profile creation method. It produces a better profile. I get stacks of RGB black and white images from my professional readers (mono accounts for 70 per cent of all UK social photography at awards/exhibition level) and with my profiles, they all look just as they should with no tint shifts at any density. That is unless the photographer has used a hardware calibrator, ended up with a tint shift in the shadows, then messed around in Photoshop trying to remove it and ended up with a red or green bias showing up in gradations. A good test of whether your monitor is correctly calibrated is simply to take any Photoshop RGB image, execute the Desaturate command, and view it. If there is absolutely no hint of any tint shift at any density, your monitor is fine and just needs a profile, not a calibration+profile. Thank you, David. This is one of the most illuminating (pun intended) threads in quite a while. I've yet to re-profile my iMac, as I've seen no problems so far with prints on my 3800. Previous Macs' monitors have been done with the Spyder. -- John McWilliams |
#8
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Calibration software for an iMAC
In article , David Kilpatrick
wrote: if it doesn't need calibrating as you say, why are you calibrating it? To create a profile - as you suggest. In fact any of the visual adjustments made on this screen are so small they may not be worth making. true, the differences from out of the box and a hardware profile are small. There is a very small difference between the default profile and the one created by the Apple utility, but there's a big difference if I use a hardware calibrator - and generally, the results are worse. then you're doing something wrong. for me the results are dramatically better with a hardware device. exactly why a hardware device is better. Far from true. it's exactly true. Hardware devices vary greatly and so does the software. while there is some variance among the different hardware devices, they are *far* more consistent than the human eye, which varies much more than even the worst hardware device, unless of course, there's a defect in the puck. for example, some of the early spyders had an issue that produced very odd results, and they would replace it with one that didn't have the problem. |
#9
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Calibration software for an iMAC
David Kilpatrick wrote:
wrote: I have an iMAC about a year old. I am trying to calibrate the monitor to assist in making photos. I have used the Spyder3 software and colorimeter in the process. The problem is that the prints all come out noticeably darker than the image on the screen. The Spyder people say this is Apple's fault. The brightness control (really the backlighting control) on the display will not sufficiently reduce the brightness to get an accurate calibration. The only work around I see is to reduce the brightness in Photoshop below what looked good on the screen and hope the printer responds by yielding a print of the correct brightness. But this adjustment is completely ad hoc and is just the kind of fiddling I hoped to avoid using the calibration routines. Two questions: 1) Does anybody have a better way to use Spyder3 to compensate for this problem? 2) If not, what alternative calibration system might be used that will avoid (or at least mitigate) this problem? I read good things about the Macbeth systems, but will they run into the same problem? Thanks for the help. First ignore all the garbage in troll replies - the iMac 24 inch screen, matt, if that's what you have, is one of the best for colour accuracy and actually doesn't need calibrating at all. I have a Spyder 2 Pro, a ColorMunki and a Huey Pro. Guess how I calibrat? I use Apple's excellent visual utility in Advanced mode, making sure I do the following: The 24" Imac screen isn't "one of the best for color accuracy". It's no better - and probably worse - than other currently available IPS panel screens of that size. The panel is made by LG China (formerly LG Philips) presumably made to Apple's specs - including price. The panel itself is probably fine. I understand that the Imac 24" backlight is an array of 3 x CCFL tubes. That's noteworthy because while (cheap) TN panel displays of that size might have 3 CCFL tubes, IPS panels displays usually have 6. Here's an article which gives a very plausible explanation for the excessive brightness: "Apple tries to compensate for this with ridiculously high level of brightness" http://www.silvermac.com/2008/24-inc...n-do-about-it/ Note the comment: "Even the lowest setting is still way way too bright for most of us". I understand that lowest setting gives around 180cd/m2. Next step up in apple hardware is probably the the 24" LED backlit ACD. Reviews state that white level can be set to appropriate levels (for "most of us" - I assume), and would hope that LED backlighting gave less non-uniformity, but AFAIK it's a white LED (as used in laptops - not the vastly better RGB LED backlit display used in professional grade LCD monitors) display, has lousy connectivity options (not a problem perhaps if you have the right mac), and lousy ergonomic adjustments (tilt only - no 180 deg swivel, and no height adjustment) and it's expensive for what you get. Please write this off as a troll post if the truth hurts. |
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Calibration software for an iMAC
nospam wrote:
while there is some variance among the different hardware devices, they are *far* more consistent than the human eye, which varies much more than even the worst hardware device, unless of course, there's a defect in the puck. for example, some of the early spyders had an issue that produced very odd results, and they would replace it with one that didn't have the problem. I have 98/100 Farnsworth-Munsell test vision and Shirley has 100/100 (plus the disturbing ability to remember colours - that is, to memorise a colour and match any time later) which I guess is one of the things which got her ahead in her Masters degree in colour science. So I may be as accurate as some calibrators. I've used many calibration systems because we are sent them to test. We did have (and still have, but unused) a neutral grey room and I'll admit I no longer use that for retouching (it is now my studio instead), but I have solid wooden shutters on the windows so my environment can be totally controlled. Putting it simply, if you obtain three calibrators and three packages to run them, then calibrate your monitor with all three, they will not produce identical profiles. I've tested this many times. Since any three or more hardware calibration devices will never produce identical results, and some are way different, I conclude that unless you have limited colour vision and really can't do the visual thing, they may not always be worth the money. Of course, if your colour vision is in the lower quartiles (which is the case for many men, especially those over 30) you won't be able to see the differences after calibration for exactly the same reasons that you couldn't use the visual calibration. What's your Farnsworth-Munsell 100 score? It would be interesting to know, because this test is something we recommend as a preliminary for studios when selecting staff to do retouching/pp work. Most universities with a colour science dept will test you. Most colour management I see are not fine-tuning issues, they are massive errors - prints far too dark compared with the screen, etc. That is rarely a calibration issue, it is nearly always a printer profile and driver settings issue. David |
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