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Author Topic: i1Profiler - i1Pro-uvcut vs. i1Pro-normal  (Read 6112 times)
rasworth
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« on: April 25, 2011, 12:08:18 PM »
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Read the targets for Red River UltraProSatin with both i1Pro-uvcut and i1Pro-normal.  The paper isn't as loaded with OB's as most rc types, but still has enough to trip the "Correct for Optical Brightener" check box in ProfileMaker Pro 5.10.  Attached is the spectral profile for bare paper from both instruments, uncut on the right.

After measurement in i1Profiler I did a data analysis comparing the two scanned measurement files - it showed a definite difference, primarily in the lighter tones, with a 2.23 delta e for the 10% highest deviating patches.  All seemed consistent to this point.

Created two identical parameter profiles with the two measurement sets, ran one test print thru both, and visually compared.  I can see no difference between the two prints - more test prints and measurements would be required to make sure, but my initial conclusion is i1Profiler is doing some sort of uv detection/compensation, and that at least for this paper the two i1Pros work equally well.

Question to the experts - other than always creating two profiles and comparing, when do you choose one i1Pro over the other?  I guess another way to ask the question is why not always use the uvcut version?

Richard Southworth

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terrywyse
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« Reply #1 on: April 25, 2011, 12:21:10 PM »
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As an expert, I never use an i1Pro except in the pressroom and on displays.....I use an iSis and capture both sets of data and then compare....I'll then decide to use one or the other "filtered" dataset or take an average of both.

In my opinion, using two different instruments, which would necessarily be the case with the i1Pro since you can't change filters, is already introducing a variable or "uncertainty" about these findings. You're better off with something like a DTP70 or iSis where you're using the same instrument for a comparison like this, with the DTP70 showing the effects of different *filtration* while the iSis would show the effects of two different *illuminants*.

Also, if you're using relative colorimetric rendering for such a comparison, I think the effects of OBAs would largely be factored out since it's essentially "zeroing out" the paper white during conversion.....absolute colorimetric would more likely show these differences since the paper white disparity would be imposed on the final rendering.

Just sayin'  Wink

terry
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Terry Wyse, WyseConsul
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Ernst Dinkla
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« Reply #2 on: April 25, 2011, 01:18:29 PM »
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The Red River Ultra Pro Satin is just one quality of an FBA paper.

It is represented here with the blue spectral plot, the Red River Artic Polar Satin is in red and the non-FBA  Canson Rag Photographique is in green. Yellow is a plot for a Baryte tile, for reference. Measured with an Eye 1 Basic UV+.

ArgyllCMS more or less cuts the FBA effect with a straight line from the high point within 650-700 Nm through the lowest point between 450-520 Nm to simulate an UV-cut spectrometer measurement. http://www.imaging.org/IST/store/epub.cfm?abstrid=22190  Actual algorithm used in ArgyllCMS has been slightly changed.

The Eye 1 Pro UV+ is basically an illuminant A spectrometer, FBA effect is not that great. The UV-cut version does not measure below 400 Nm.


met vriendelijke groeten, Ernst

New: Spectral plots of +250 inkjet papers:

http://www.pigment-print.com/spectralplots/spectrumviz_1.htm
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rasworth
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« Reply #3 on: April 25, 2011, 01:20:00 PM »
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I removed two previous posts, they were  not well thought out.

My question had to do with the use of i1Pros, I did not ask if there were better methods of measuring profiles.  Therefore IMO your response was not helpful.

Richard Southworth
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terrywyse
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« Reply #4 on: April 25, 2011, 01:20:03 PM »
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Mileages may vary of course.....but frankly I've not had any obvious OBA correction issues since switching to MonacoPROFILER some years back and most recently (4-5 years?) getting the iSisXL....but this was a farily common occurence with PM4/5. All I know is that I would put a spectro to my head and shoot myself if I had to use an i1Pro on a daily basis....but that's neither here nor....there.  Smiley

On the other hand, I tend to be in the inkjet proofing world and OBAs are not quite the issue as they might be in the photographic world.....we mostly have good medias available without "glaring" amounts of OBAs.....so there you have it.

Regards,
Terry
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Terry Wyse, WyseConsul
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Scott Martin
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« Reply #5 on: April 25, 2011, 04:07:32 PM »
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Really short response: always use the UV Cut - unless you taking spot measurements where you want to use the OBA effects.
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rasworth
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« Reply #6 on: April 25, 2011, 04:28:55 PM »
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Scott,

Any advice about which to use for monitor calibration/profiling?  I have read conflicting opinions as to advisability, I've had no problems using the normal i1Pro, more just curious about in the field experience.  If the uv filtering is done on the lamp, than I would think there would be no effect on display profiling, other than the instrument calibration still uses the internal light source.

Richard Southworth
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Scott Martin
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« Reply #7 on: April 25, 2011, 04:36:22 PM »
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I've seen no effect for display profiling, but I have to admit I prefer a great colorimeter to a spectro for display calibration, along with software that performs an iterative calibration process.
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jaapb
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« Reply #8 on: April 26, 2011, 12:49:05 AM »
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I've seen no effect for display profiling, but I have to admit I prefer a great colorimeter to a spectro for display calibration, along with software that performs an iterative calibration process.

Scott,

For wide-gamut displays you are probably better off with a spectrophotometer.
http://www.argyllcms.com/doc/WideGamutColmters.html

Jaap
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Jalok
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« Reply #9 on: April 26, 2011, 07:56:22 AM »
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Created two identical parameter profiles with the two measurement sets, ran one test print thru both, and visually compared.  I can see no difference between the two prints - more test prints and measurements would be required to make sure, but my initial conclusion is i1Profiler is doing some sort of uv detection/compensation, and that at least for this paper the two i1Pros work equally well.

I have done some comparison tests between i1Profiler and ProfileMaker profiles built from the same measurement data taken by an i1Pro non-UVcut. The conclusion is i1Profiler surely has something like PM's optical brightener compensation ("Correct for Optical Brightener" function). For two different and highly OBA charged papers (one matte another rc), and for two different ink sets (OEM and non-OEM Canon CLI-8 inks), i1Profiler with null value for "neutralize gray" parameter gave me identical or very very similar softproofing and printed results regarding to OBA compensation as PM did with its "Correct for Optical Brightener" function enabled. Also, by experimentation there were no i1Profiler settings which could reproduce the yellowish results printed from a PM non-COB profile. So I concluded the i1Profiler lack of a on/off brightener compensation should not be missed, unless someone needs non-COB results for special purposes. Should be said I only used perceptual rendering for the referred softproofing and printing comparisons. Maybe i1Profiler OBC-like feature does not work with the other rendering intents.
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Scott Martin
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« Reply #10 on: April 26, 2011, 08:23:35 AM »
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Scott,For wide-gamut displays you are probably better off with a spectrophotometer.
http://www.argyllcms.com/doc/WideGamutColmters.html

The Spyder3 is the exception to this rule. It's unusual 7 sensor design make it unusually well qualified for calibrating wide gamut displays. In fact, it's able to measure subtle low light differences better than a common spectro like the EyeOne. The shadows come out exceptionally well. Try a comparison for yourself! Whatever device you use, make sure you use an iterative calibration process - I find that goes a long way towards achieving smooth gradations.
« Last Edit: April 26, 2011, 01:09:54 PM by Onsight » Logged

jaapb
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« Reply #11 on: April 26, 2011, 01:04:56 PM »
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The Spyder3 is the exception to this rule. It's unusual 7 sensor design make it unusually well qualified for calibrating wide gamut displays. In fact, it's able to measure subtle low light differences than a common spectro like the EyeOne. The shadows come out exceptionally well. Try a comparison for yourself! Whatever device you use, make sure you use an iterative calibration process - I find that goes a long way towards achieving smooth gradations.

Thanks Scott,

I wasn't aware of that, I don't have a Spyder3 (yet) maybe in the near future I will do the comparison.

Jaap
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Ernst Dinkla
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« Reply #12 on: April 26, 2011, 03:11:24 PM »
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The Spyder3 is the exception to this rule. It's unusual 7 sensor design make it unusually well qualified for calibrating wide gamut displays. In fact, it's able to measure subtle low light differences better than a common spectro like the EyeOne. The shadows come out exceptionally well. Try a comparison for yourself! Whatever device you use, make sure you use an iterative calibration process - I find that goes a long way towards achieving smooth gradations.

AFAIK, a colorimeter 3 to 7 LEDs / sensor combination still has to be adapted for that wider gamut RGB emission and in that adaption it will not be right for a normal gamut. With several display gamut sizes in use now and deviations between individual colorimeters it has to be seen whether the Spyder 3 is always correct. ArgyllCMS has a compensation setting for colorimeters. It is correct that a colorimeter is better at low light differences than a spectrometer.

It is better explained here:
http://hoech.net/dispcalGUI/


met vriendelijke groeten, Ernst


New: Spectral plots of +250 inkjet papers:

http://www.pigment-print.com/spectralplots/spectrumviz_1.htm
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Ernst Dinkla
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« Reply #13 on: April 27, 2011, 02:58:12 AM »
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So I concluded the i1Profiler lack of a on/off brightener compensation should not be missed, unless someone needs non-COB results for special purposes. Should be said I only used perceptual rendering for the referred softproofing and printing comparisons. Maybe i1Profiler OBC-like feature does not work with the other rendering intents.

The common conclusion in all the forums seems to be that UV-cut profiles (in what way they are created doesn't matter here) make prints that are generally more pleasing to look at under varied consumer lighting conditions. I guess that does not include going through photo albums on the porch. What surprises me more is that 99% of RC papers has FBA content, 20% deliver b -10 brightness. A lot of other paper qualities rely on it too. We do not get other papers (excluding the ones for archival reasons) and we seem to like what actually warps colour management, a profile made for a "neutral" paper while the paper varies from b -2 to -10. And I know from practice that even indoors FBA effect is seen with RC papers. More subtle profiling features like adapting the grey axis to paper white starts in that case with data that is already compromised. I am actually not questioning the consumer's eye sight or the experts' vision on it but question why this practice isn't discussed as being warped CM. The more I read and learn about CM, the more I get the impression that it isn't a hermetic system in its fundamentals (for example: Delta E is not the same throughout the space) and CM practice saws on the other legs of the stool.


met vriendelijke groeten, Ernst


Dinkla Gallery Canvas Wrap Actions for Photoshop

http://www.pigment-print.com/dinklacanvaswraps/index.html

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PhilipCummins
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« Reply #14 on: April 27, 2011, 06:53:46 AM »
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Any advice about which to use for monitor calibration/profiling? I have read conflicting opinions as to advisability, I've had no problems using the normal i1Pro, more just curious about in the field experience.  If the uv filtering is done on the lamp, than I would think there would be no effect on display profiling, other than the instrument calibration still uses the internal light source.

From what I've read either UV-cut or No-Filter works fine for display calibration & profiling, the filter itself only affects the internal i1Pro light source, the central reading aperture is clear on both versions.
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rasworth
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« Reply #15 on: April 27, 2011, 08:22:22 AM »
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Yes, but ...  I've read opinions both for and against.  My only concern would be the effect of the uv filter upon calibration of the i1Pro just before monitor profiling.  I don't know how sharp the uv filter is, i.e. does it affect some of the visible blues, and therefore might impact the accuracy of calculating the blue primary.  I would think it would be a second order effect at worst, but I haven't really tested.

I attached the spectrum plot of my display white (measured with a normal i1Pro), running at 5500K.  It pretty well covers the sRGB gamut, a wider gamut display might have stronger blues farther down in the spectrum.  If the uvcut instrument mis-reads too many slices at the blue end because of inaccurate calibration it could affect the results.  Probably just of academic interest, most will use either a colorimeter or a basic i1Pro for monitor calibration/profiling.

Richard Southworth
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Ernst Dinkla
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« Reply #16 on: April 27, 2011, 08:46:19 AM »
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the central reading aperture is clear on both versions.

Not according to this article:

http://rmimaging.com/information/Chromaxion_Issue_1.pdf

It could still have a compensation for that blue or that blue may not affect the display calibration but it is not clear.


met vriendelijke groeten, Ernst


New: Spectral plots of +250 inkjet papers:

http://www.pigment-print.com/spectralplots/spectrumviz_1.htm
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Scott Martin
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« Reply #17 on: April 27, 2011, 11:00:07 AM »
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Richard you've got me thinking, so I've been doing a fresh round of testing this morning with my UV Cut i1 and Spyder 3 with i1Profiler, DispCal, Color Eyes Display Pro, and Spyder3Elite. I'm using i1Profiler for statistical analysis and my evaluation image in Photoshop with and without soft proofing for visual analysis. 

I'm pretty stunned with what I'm seeing out of i1Profiler so far. Not only does the process take less than 2 minutes (!!) but the shadows and smoothness are incredible, rivaling even DispCal's hour long calibration process. i1Profiler's QA analysis reports lower Average Delta E variations with i1Profiler's calibration than the others. I've been frustrated with shadow detail from the i1 Pro in the past but i1Profiler is doing a better job than I've seen with previous solutions.

I'm continuing to test as the number of possible combinations is quite numerous. For example, can the results of a colorimeter be equal to that from i1P/i1Pro when a DispCal colorimeter adjustment is applied? How do all of these results average when we include a large number of display into this testing? It will take time to answer these questions.

It's pretty clear at this point that if you already own a UV Cut i1Pro and i1Profiler, I'd say that's an excellent single solution that you could feel really good about using for calibrating not only printers but displays (small and large gamut) as well. It's simple, fast, and the results are visually and statistically fantastic in comparison to many of the leading options.

For those that don't own an i1Pro and I1Profiler, there are several excellent options from Spyder3Elite (best value, easy to use, cost effective), to ColorEyesDisplayPro and BasICColor (more geeky and more expensive) and lastly DispCal (super geeky but supports lots of devices). And of course there are proprietary solutions like those from NEC, EIZO and Barco. What a complicated landscape this has become!
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VitOne
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« Reply #18 on: April 27, 2011, 11:01:34 AM »
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I am not an expert but I'll give you my two cents.

I don’t own an i1Pro with UV filter, but I own a ColorMunki. I never understood how similar this 2 instruments are, I read many different opinions. I also made a “comparative test” in the past: http://www.luminous-landscape.com/forum/index.php?topic=50214.0

I made some profile, using Argyll and starting from the same 2000 patches, with the i1Pro (with and without FWA compensation) and ColorMunki.

I used a GrafiLite Mode (Ott-Lite, see this: http://photo.net/digital-darkroom-forum/007Ue2) and natural solar light to look at the prints (I printed a test image with RelCol and AbsCol from Photoshop with BPC for each profile). I think that the best prints where the one made from the i1Pro –f profile (Argyll FWA compensation). They looked more neutral that the one from the ColorMunki and the one from the i1Pro without FWA, in the BN I saw no particular cast in the –f profile.

I did this simple and stupid test.

This is the test image:


Made with Canon 1D Mark III, 24/70 2,8, DNG profile using CC Passport. Light from the window.

Image is ProPhotoRGB, 16bit, opened in Photoshop.

Print made with an Epson 790, OEM Ink, Hanhemuhle FA Baryta paper.

The paper has some OBAs, as you can see using this online plotting tool: http://www.pusztaiphoto.com/articles/printing/spectrums/webchart.aspx

The upper part is a print made with i1Pro, ArgyllCMS and FWA compensation ON (for D50 illuminant).

The lower part is a print made with the ColroMunki. The profile, the test chart, all the setting where the same. Both the profiles have very good DeltaE 2000, max is below 1,5 (and average is in both profile below 0.6), i1Pro profile is a little bit better comparing numbers.

Here you can see the BW part of this image “averaged” with Photoshop.



The image that you see here is in sRGB space, the reported values are from the original file (ProPhotoRGB).
As you can see my impression of a bluish cast in the CM profile is confirmed by the data. I don’t know how the i1Pro UV Cut would behave, but asking several people I trust, I always got suggestion about buying an instrument with no filter, so that the “profiling program” could care of OBAs. Graeme Gill (ArgyllCMS author) recommends to use non-filtered instruments: http://www.argyllcms.com/doc/FWA.html
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Scott Martin
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« Reply #19 on: April 27, 2011, 11:19:02 AM »
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Good testing there, but so many more variables to continue testing! I'd also like to see some spot spectro measurements of those grays. You've shown the need for OBA/FWA correction, but haven't tested hardware via software solutions. Sure Graeme is going to suggest an unfiltered device, particularly because his solutions provide software based corrections. But what about i1Profiler that doesn't have a software based solution? I'd like to see a comparison of your UVin Argyll profile to a UVex i1Profiler profile. And another comparison of the two apps comparing both the Perceptual and Relative Colorimetric intents. I'd like to see that, just for starters. :-]

For the sake of the OP, I think all the evidence is showing that his UVCut/i1Profiler purchase was an excellent one that he can use for nearly all of his work.

If we were to ask "What's the right solution for me?" I'd think we'd have to ask who "me" is. If "me" is a demanding print and image maker with a thirst for travel we might come up with one solution. If "me" is a retired amateur color scientist with a thirst for hours of statistical analysis we might have a different set of solutions. Some of us just have to find that sweet spot in the middle.


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