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Author Topic: Consistent Printed Image Discrepancies Using QU  (Read 13680 times)
Roger1122
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« on: February 23, 2012, 08:04:58 AM »

I hope that was a sufficiently provocative title to get the experts reading this post! I am tremendously impressed by QU, but I am consistently running into a problem with using it.

The problem is that my printed images are consistently slightly darker than my screen previews. To get them to print with the proper shadow density and general tone, I have to make the screen preview lighter than appropriate.

I have calibrated and re-calibrated my LCD, and upgraded from Datacolor Spyder 3 Pro to Spyder 3 Elite (a US$99 software upgrade) before recalibrating. I have profiled my printer/paper combination using the Datacolor Spyder 4 colorimeter. I have made sure that the monitor profile, the image colour space (Adobe RGB) and the printer/paper profile are all in their proper places. And I must say this is not only a QU problem. The images look fine in PhotoShop, but still come out too dark. Of course I wouldn't want to go back to printing in PS after having once tasted the convenience and flexibility of QU. But I am really frustrated by this persistent problem. I can fudge it by guessing how much lighter I have to make the images appear to get the right print density, but that's a slippery slope to start down, and it's a variable I want to eliminate.

Could it be the very variable levels of lighting in my home office? That's the only thing that occurs to me, but there doesn't seem to be any immediate correlation between lighting levels and print darkness. Any and all suggestions welcome! Or should I look into the Epson "advanced" ink density settings? Argh!!!
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Fred A
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« Reply #1 on: February 23, 2012, 10:05:47 AM »

Quote
Could it be the very variable levels of lighting in my home office? That's the only thing that occurs to me, but there doesn't seem to be any immediate correlation between lighting levels and print darkness. Any and all suggestions welcome! Or should I look into the Epson "advanced" ink density settings? Argh!!!

Hi Roger,
It has been my experience over and over, that the monitor is too bright!
I don't pretend to know the abilities of all the profiling packages that have come out lately which purport to read the brightness and allow that to be set, but I don't own such a sophisticated version as of yet.
I hope Terry gets on here. He has a profiling tool that does address the brightness.

In my case, I use a premade Epson Profile for Premium Luster and also Premium Glossy. I make test prints. If the prints appear too dark, compared to the monitor, I take the approach that Epson put some quality effort into making the profiles for my printer and their paper.
I assume the print is correct!
Once I get past that, I turn the brightness down, (usually to about 40-45%) and I also pay attention to the shadow detail and highlight detail and adjust the contrast to match too. (Usually close to 80%.

*NOW* I profile the monitor for color accuracy, and it works for me.

Terry will be along shortly, I'm sure. He has an iMatch thing that sets brightness.
So hang in there.

Fred
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Terry-M
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« Reply #2 on: February 23, 2012, 11:34:03 AM »

Hello Roger,
Fred is right, dark prints are usually caused by too bright monitors and users adjusting the image to the monitor, making it darker, so the print comes out dark.
I have an Eye One 2 Display calibration device and the software, in advanced mode, allows you to set the luminance (brightness). My software says the recommended value for LCD monitors is 120 CD/Msq. I find this works well. However, because I'm working with a "number" and relying on the calibration device, I believe that is more consist ant than doing things by eye. If you have to change the brightness to match prints, you change the target luminance value and calibrate accordingly and thus know where you are and can be consistent.
Does you software allow setting luminance, I'd be surprised if it does not?
One other point: -
Quote
Could it be the very variable levels of lighting in my home office?
That is possible. It's best to check under consistent conditions and bright daylight is good. However, it's not always possible to do that so I recommend getting an Ott Light. These are relatively inexpensive and give you a colour temperature & spectrum close to daylight and the "correct" brightness for viewing a print.
Terry
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Roger1122
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« Reply #3 on: February 24, 2012, 12:33:50 AM »

Thanks Fred and Terry. I'll reply to you both in this note, since you both mention monitor brightness. I am very much aware of the problem caused by a monitor that is too bright. I went to the Epson "Epsite" showroom, exhibition and support site in Tokyo and it was the first thing they told me, and said that unless you profile your monitor and adjust its brightness there is NO WAY to secure consistent prints. So I bit the bullet and bought a DataColor Spyder monitor profiler. This does include a brightness setting, which currently is set to 120CD/MSQ. This is on the calibration I did yesterday, when the light was still quite bright. Last month I did a profile in the evening and the level was set to 90. But at that time I did not have the printer/paper profile right and there were other things wrong with my prints than darkness. <wry grin>

Your comments encourage me to believe I was on the right track suspecting the variable level of room lighting. I live on the top floor of a large condominium in suburban Tokyo, and all morning the sun streams directly into the room. Even with the curtains closed, the ambient light level is reported by the Spyder as "Extremely bright--unsuitable for accurate colour management." But we use indirect lighting in the room, and the general level is very low once we have to switch the lights on. Spyder called this level "Low--ideal for accurate colour management."

Incidentally, the technical expert at DataColor with whom I corresponded was not impressed by the accuracy of Epson printer/paper profiles, saying they were a good first approximation (!) but could benefit from detailed tweaking using a colorimeter. These are much more expensive than the monitor calibration device but fortunately I was able to get mine secondhand from a professional photographer friend who has gone over to a pro lab for all his exhibition prints and no longer needs to profile his own. Support from Datacolor was excellent, just as if I had bought it new directly from them... they even gave me a registration code for software that had been upgraded since my unit was sold.

I'll also mention that the prints are not very much too dark, just slightly (but noticeably) darker than they should be. Looking at them in the bright sunlight streaming through my windows this morning they really don't look too bad although yesterday evening when I showed them to my wife they looked rather worse. I think what I should do is profile the monitor in the evening, when the lighting level is low, and set up the image files for printing during the daytime, when I will probably have to make them brighter. That way I may get prints that look a bit too bright or "thin" under bright daylight but look fine under artificial light. That's a more acceptable compromise than what I have now.

My budget for equipment is spent out right now but I'll certainly look into Ott lights. If "inexpensive" means the same thing to you and me, Terry, I'll get one from next month's budget. I'm a pensioner, so I have to watch the pennies.
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Terry-M
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« Reply #4 on: February 24, 2012, 08:47:19 AM »

Hi Roger,
I'm fortunate that my monitor has auto brightness so the brighter the ambient, the brighter the screen gets & visa-versa. However, I turn this off when calibrating which is done in a semi-darkened room. I also have a monitor hood which I made myself from 5mm black foam board and the odd bit of wood to stiffen it. It even has a hole in the top for the calibration puck to pass through.
The auto-brightness feature seems to work quite well.
Regarding Ott Lights, in the UK, one for A4 size prints is about 50 and an A3 size about 90.
Terry
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Fred A
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« Reply #5 on: February 24, 2012, 11:34:38 AM »

Quote
Incidentally, the technical expert at DataColor with whom I corresponded was not impressed by the accuracy of Epson printer/paper profiles, saying they were a good first approximation (!) but could benefit from detailed tweaking using a colorimeter.

Roger,
I don't have any affiliations with Epson at all, but for the Data Color technician to make that statement sounds a bit self serving since they sell profiling tools.
I also have to disagree based on common sense and my experience.
Not only do I use Epson paper, but I have a decent selection of Ilford Glossy and Ilford Pearl. I also have some HP glossy.
My experience shows me that a print on Ilford Smooth Gloss using their profile supplied by Ilford for their paper and my printer, and printing the same image on Epson Prem Glossy using their profile for my printer yields identical prints.
So for me to accept the words ot the technician at Data Color is to throw away the evidence that both profiles produced the same prints.
That leaves us with the choice: both profiles were independently wrong, or  the Data Color guru was trying to push you toward buying some product.

Ilford would strive to make their profiles perfect to ensure that you will like the results and buy more paper.
Epson probably sells more medium and higher end printers than all the rest, and it behooves them to make the profiles accurate for the same reason, a happy customer, buys more ink and paper.

I don't really blame the Data Color guy...  Shocked   since, many times, I try to ask people to try Qimage Ultimate and hope they like it as much as I do.

Fred

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Roger1122
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« Reply #6 on: February 24, 2012, 02:25:47 PM »

Hi Roger,
I'm fortunate that my monitor has auto brightness so the brighter the ambient, the brighter the screen gets & visa-versa. However, I turn this off when calibrating which is done in a semi-darkened room. I also have a monitor hood which I made myself from 5mm black foam board and the odd bit of wood to stiffen it. It even has a hole in the top for the calibration puck to pass through.
The auto-brightness feature seems to work quite well.
Regarding Ott Lights, in the UK, one for A4 size prints is about 50 and an A3 size about 90.
Terry

Thanks, Terry. My Spyder puck has an ambient light measuring capability, so the profile suits the ambient light at the time I made it, but of course if the light changes dramatically during use, as it does throughout the day, then the profile will not always be suitable. I am thinking of making two profiles, a dim light one and a bright light one. But I'm already at the place of diminishing returns. The photo club meet at which I have to present two prints for adjudication is tomorrow, and I'm ready for that. As ready as I'll ever be, anyway. And it's possible to get too fussy about print quality. Frankly I'd rather be out taking photos than fussing over prints in a darkened room. <sigh> But the Epson people also recommended using a monitor hood, and all their monitors had them. I'll have to see what I can do...

On the other hand I find I am getting pretty consistent results preparing the images in PS, transferring them to Qimage U for printing, and adding 3 to 5%"fill" as a filter. This gives me prints that are quite close to the PS image but lighter than looks good with Qimage. So I might just do that, if it turns out that this is consistent.

Ott lights at 50GBP look a little too expensive for me right now. Maybe for my birthday in August? Everything is usually more expensive here in Japan even though our VAT is only 5% for now (going up to 10% shortly, though).
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Roger1122
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« Reply #7 on: February 24, 2012, 02:50:33 PM »


Quote
I don't have any affiliations with Epson at all, but for the Data Color technician to make that statement sounds a bit self serving since they sell profiling tools.
I also have to disagree based on common sense and my experience.
Not only do I use Epson paper, but I have a decent selection of Ilford Glossy and Ilford Pearl. I also have some HP glossy.
My experience shows me that a print on Ilford Smooth Gloss using their profile supplied by Ilford for their paper and my printer, and printing the same image on Epson Prem Glossy using their profile for my printer yields identical prints.
So for me to accept the words ot the technician at Data Color is to throw away the evidence that both profiles produced the same prints.
That leaves us with the choice: both profiles were independently wrong, or  the Data Color guru was trying to push you toward buying some product.

Ilford would strive to make their profiles perfect to ensure that you will like the results and buy more paper.
Epson probably sells more medium and higher end printers than all the rest, and it behooves them to make the profiles accurate for the same reason, a happy customer, buys more ink and paper.

I don't really blame the Data Color guy...  Shocked   since, many times, I try to ask people to try Qimage Ultimate and hope they like it as much as I do.


Actually I was very impressed with the DataColor guy. He seemed to have integrity and he was both knowledgeable and extremely helpful to me. And he did say they were a GOOD "first approximation." But he was also talking about their applicability to papers of the same general class made by other manufacturers, and saying that you just couldn't expect them to be appropriate. I would go along with that. I did try an Ilford "Pearl" paper because I heard it resisted metamerization, but the entrance grade of Epson glossy does fine for me at about half the price. Unfortunately Epson has NOT upgraded the profiles they originally provided with my PM-4000PX, and most of them have been replaced with different papers, for which the profiles cannot be expected to apply. This was the context of his advice. I don't think he was running Epson down and he certainly thought very highly of their printers, owning one himself!

Also I might point out that the profiles could be consistent in use and with each other and still not actually optimum. It's a possibility, though unlikely, I agree.

Also I had already bought my equipment, so he wasn't trying to sell me anything. I worked for Epson for years, translating most of their early catalogues on computers from Japanese into English, and I loved working for them and have the greatest respect for the company. That was as a subcontractor, of course, not as an employee. I helped the inventor of the ink-jet printer, who was their research director, to present speeches at international conferences. But that was in an earlier lifetime. <grin>
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Terry-M
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« Reply #8 on: February 24, 2012, 03:57:28 PM »

Hi Roger,
Quote
My Spyder puck has an ambient light measuring capability, so the profile suits the ambient light at the time I made it
I personally don't think that is a good idea because, as you say ambient varies so much in everyday conditions and it seems impractical to make different prints for different conditions as a general rule. It may be justified for a print that is going to hang in an unusual environment for some while.
My calibration device can measure ambient too but I never use it because the readings vary so much.
I like to work to a standard and the Ott light gives me that as a "cheap" alternative to a professional viewing booth. I'm fortunate in that my work flow produces consistent print compared to screen so it's not often I have to check now.
My photographic club uses a daylight viewing stand in a darkened room for print judging; the brightness must be ok. as mine, and other prints, always look as they should under it. You can more problems with projected images; it's not uncommon for them to be too bright.
Terry
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Roger1122
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« Reply #9 on: February 25, 2012, 02:29:19 AM »

Quote
I personally don't think that is a good idea because, as you say ambient varies so much in everyday conditions and it seems impractical to make different prints for different conditions as a general rule.

My problem is getting the prints to look like they do on the monitor. The ones that do, look pretty good under all kinds of lighting, but the ones that don't, look bad under almost all lighting! I was hoping that by having the monitor calibrated for when I use it under extremely bright conditions, and again for our usual evening low-light conditions, I could get consistent prints!

But now I've had a different idea. I note the brightness setting that Spyder tells me gives 90CD/MSQ and the one it says gives me 120CD/MSQ as percentages on my LCD monitor controls. Spyder instructions tell you never to alter the settings once you have calibrated the monitor, but if I just note and use the monitor brightness control and set it to the two different percentages (they are about 53% and 94% respectively) then I can make the monitor dim or bright as appropriate and (hopefully) get consistent prints. "Dim" just generally seems better all round, so I may just stick with that. There may be some secondary effects, i.e., changing the brightness may slightly modify the spectral response, but I do notice that the colour gamut shows IDENTICAL coverage of colour space, very close to Adobe RBB, for both the 90 and the 120 calibrations, so I'll take that chance.
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Fred A
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« Reply #10 on: February 25, 2012, 10:29:59 AM »

Quote
ou never to alter the settings once you have calibrated the monitor, but if I just note and use the monitor brightness control and set it to the two different percentages (they are about 53% and 94% respectively) then I can make the monitor dim or bright as appropriate and (hopefully) get consistent prints. "Dim" just generally seems better all round, so I may just stick with that. There may be some secondary effects, i.e., changing the brightness may slightly modify the spectral response, but I do notice that the colour gamut shows IDENTICAL coverage of colour space, very close to Adobe RBB, for both the 90 and the 120 calibrations, so I'll take that chance.

Roger,
You are reversed!
You should be trying to get the monitor to look like the prints, not trying to make the prints look like the monitor

Quote
my problem is getting the prints to look like they do on the monitor. The ones that do, look pretty good under all kinds of lighting, but the ones that don't, look bad under almost all lighting! I was hoping that by having the monitor calibrated for when I use it under extremely bright conditions, and again for our usual evening low-light conditions, I could get consistent prints!

I think you are getting close though.
If you choose the lower setting, the one that works out to be about 53% on your software, and stay with it, and then profile the monitor,You should be very close.

Then just do the color profiling part of the process.

Good topic.

Freed
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Roger1122
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« Reply #11 on: March 05, 2012, 12:17:34 AM »

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You are reversed!
You should be trying to get the monitor to look like the prints, not trying to make the prints look like the monitor

Fred, sorry for the delay in this reply. Several things came up that kept me away from the computer. Hope you're still in the loop. I seem to have misled you. My desire to make the monitor and the prints look like each other naturally and inevitably requires that I have a monitor that shows images which will THEN result in prints that look as near the same as possible on both screen and paper, considering the different contrast range, etc., of additive and subtractive images. The monitor has to come first. The only reason for trying to tweak the monitor so that it looked like my best prints was to try to get a handle on what settings would give me a consistently achievable likeness in other, later, prints from the same monitor. As I see images FIRST on the monitor and THEN as prints, I have to make all my tweaks on the image I see on the screen! So I want to set and forget the monitor profile.

I am now pretty happy with the print quality I am getting, and Qimage is a major help. I have settled on 90cd/sqm as the best compromise monitor profile brightness, with +3 "fill" applied at print time by Qimage. By the way, I was disappointed with the reception given to my prints at the first photo club meeting. Neither got even a "mention" in the rankings and one elderly expert kindly suggested I might like to bring along some more snaps at their next meeting. Argh! One problem I have in relating to other photographers is that most of my efforts go into making VR panoramas (you can see some at Microsoft's photosynth.net site in the "Rogerama" collection). But now I can produce prints with consistently high quality I am getting a lot more fun out of the more conventional side of photography. I've been going back over the last few years looking at the "snaps" I took on the side at various panorama shoots, and printing them. For the next photo club meet I will be taking along a triptych I took of the London "Big Eye" ferris wheel, from along the embankment, from the top of the ride, and looking up through the structure from ground level. Let's see what they think of that. The prints are--though I says it mesel' what didn't oughta--quite beautiful.
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Terry-M
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« Reply #12 on: March 05, 2012, 08:14:59 AM »

Hi Roger,
Quote
As I see images FIRST on the monitor and THEN as prints, I have to make all my tweaks on the image I see on the screen! So I want to set and forget the monitor profile.
What you describe is a work flow but there are two independent processes taking place.
The first is what appears on the monitor and is controlled by the monitor settings and its profile; the second is the print controlled by the driver settings and the printer profile.
With particular reference to monitor brightness and dark prints: -
You don't/cannot normally adjust a printer profile so that is fixed, in other words the print is the bench mark. The only thing left to adjust is the monitor that is why Fred said make the monitor look like the prints.
Quote
with +3 "fill" applied at print time by Qimage
I used to do that but a new monitor seemed to make the need to do that disappear.
Terry
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Roger1122
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« Reply #13 on: March 05, 2012, 09:19:41 AM »

Quote
What you describe is a work flow but there are two independent processes taking place.

Wow, yes. I think I finally got it. Thanks, Terry. What you are saying is, if the printer/paper profile I have painstakingly prepared by reading several hundred colour patches results in dark prints, adjust the monitor until it shows dark images! I had both parts of the problem clear, but I was taking the work flow as the decisive factor in deciding the order in which to settle them. But I do think I got the monitor problem right: calibrating it for a brightness that is higher than I really need.

It could also have something to do with the angle at which I view the screen. In the "advanced" tools that came with my upgrade of the Spyder profiler there is one to measure the evenness of the screen illumination. Mine is much dimmer in some areas than others (it's a low-price DELL 22" LCD) so it matters where the important image content comes, as the calibration is only true for the narrow central region of the screen. This interacts with the added loss of brightness you get when you are looking at the screen at an angle. <sigh> NOTHING about colour management is simple. That's why it's SO MUCH FUN. (Ha ha!). This year I upgraded my computer. Next year (she-who-must-be-obeyed permitting) I will upgrade my display.

Great forum. Great help. Great product!
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Terry-M
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« Reply #14 on: March 05, 2012, 10:39:26 AM »

Hi Roger,
Change of subject here  Roll Eyes
Quote
most of my efforts go into making VR panoramas (you can see some at Microsoft's photosynth.net site in the "Rogerama" collection).
I've had a look at your stitched images & pano's etc. Very good and interesting locations!  Cool
What software do you use for stitching?
In recent months I have been "playing" with stitched images and using Microsoft Ice, not as dramatic as yours though.
Photosynths http://photosynth.net/userprofilepage.aspx?user=terrym12&content=Synths
Gallery: http://www.pbase.com/tjm04/panos
Quote
Neither got even a "mention" in the rankings and one elderly expert kindly suggested I might like to bring along some more snaps at their next meeting. Argh!
I find Elderly experts can be stuck in their ways, not that applies to me or Fred of course  Grin Just enjoy your photography and making prints; if a judge likes one, great, but if not, that's only his or her opinion. Has your club got a web site? Mine's here http://www.dunchurchps.com/content/index.php
Terry
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