CHROMiX

Monitor Calibration Software That Supports Spectro Profiling

Hi,

so far I’ve been using an i1 Display Pro either with Color Navigator 6 (for an Eizo CG275W) or basICColor 5 (for my 3 other computer monitors).

I just purchased an i1 Pro spectro, which I want to profile the i1 Display Pro against to improve color accuracy.

I have looked in Color Navigator and basICColor and I cannot find any options for this… is this possible with these calibration packages ?

Other TV set calibration packages (Calman, Chromapure etc.) support spectro profiling, which also eliminates the drift of the colorimeter over time…

If profiling is not possible in basICColor 5 or CN 6, are there any other commercial monitor calibration packages that do support it ?

If not, is there a workflow in BC 5 or CN 6 to modify / update just the gamut with the spectro on a finsihed calibration ?

Thanks for your input.

  • M

just to clarify: I want to profile the colorimeter against the spectro - the software will create a compensation profile for the color drift of the colorimeter - and use that compensation profile to get much more accurate calibration results.

Any suggestions ?

What exactly do you mean when you say that you say that you “just purchased an i1 Pro spectro, which I want to profile the i1 Display Pro against” to improve colour accuracy?

A measurement device itself can’t be profiled as only RGB/CMYK/similar devices can have a profile made for them.

In a sense, one could argue that all colour measuring devices already have a kind of profile associated with them, for lack of a more appropriate term, as eloborated upon in the device specifications. As an example, an i1Pro might have the ability to measure from 380nm to 730nm, in 10nm bands. This essentially is a kind of profile in a manner of thinking, in that we now know the exact input colour space - all visible light broken down into 10nm bands. That’s the character of the device and profiling, after all, should more correctly be termed characterization, as that is what’s being done when measuring a target and creating a profile.

But back to your query, I can’t really understand how one would even go about making a profile for any colour measurement device? There’s certainly no profiling software I’ve ever heard of which has any such capabilities.

No, and not with any other apps on the market, that I’ve heard of or used.

If not 100% of available profiling software, then the huge majority most definitely do support and allow the use of an i1Pro spectro for creating profiles. The device has been the most popular spectro/colour measuring device in the photographic and fine art/graphics/similar printing user demographic. For about the past 10 years of so, the i1Pro has the the defacto industry standard measuring device, even though it is definitely nowhere close to being in the top-end or top of the range spectro device available, whatever the metric - accuracy, repeatability, inter-instrument agreement, etc. It’s basically the cheapest device capable of creating decent to excellent quality input and output profiles.

Regarding eliminating “the drift of the colorimeter over time”, how exactly would one device have any influence over a different physical device? And when you mention the drifting over time, how long are you thinking of? The i1Dpro should be extremely accurate for at least 5 years, if the much older i1D2 is anything to go by. You really shouldn’t be experiencing too much, if any drift over time with the i1Dpro and perhaps get it professionally inspected if you do think it’s starting to drift.

Also, by the time a device like the i1Dpro starts to drift by a noticeable amount, I’m sure there will be far newer and better/more accurate devices available in the same price range. We all know how fast all electronics technology advances and improves.

As mentioned above, most every profiling app available will undoubtedly support the i1Pro spectro.

It’s never such a good idea to create a profile with one device and then do anything else to said profile using any other device. For a start, this will introduce device inter-agreement errors in 100% of circumstances. It isn’t even possible to manufacture a $40,000 lab grade spectrometer that has 0dE inter-device agreement difference. There will always be some inherant difference and when going from one measurement technology to a completely different form of measurement device technology, this will just compound the errors and dis-agreement between the 2 devices.

As a final note, I think you are most definitely worrying about something almost completely inconsequential for 99.9% of users. It has been documented that the i1Dpro is an extremely accurate device, so much so that it performs, on average, within 0.2dE2000 and a maximum of 0.5dE2000 compared to the 400% more expensive BasICColor Discus. It is certainly far more accurate than the i1Pro when used for screen/emission measurements. Almost by an order of magnitude, in fact(!!).

The only profile creation application I’ve used that has something that might be what you’re trying to achieve is ArgyllCMS/dispcalGUI. It provides a facility to make a correction matrix for a colorimeter, using a spectro. But by using the i1Pro as the reference device, I don’t see what there is to be gained, since the i1Dpro is so much more accurate.

Hope this helps you out somehow.

aaron125,

profiling colorimeters to spectros is the de factor workflow for advanced TV set calibration - which is a much more complicated task (3-4 hours by a pro with very expensive equipment) than computer screen calibration, which is done in 5 min automatically.

Spectros measure the actual spectrum to determine color values, colorimeters have built in filters with pre-determined, fixed data (also called TABLES) most of the time created from a BROADBAND CIE Illuminant A source of light. Huge problem is, that that works better on some display types and really bad on other ones. Display types obviously vary from LED, CRT, mercury spectra (as used in some projectors), CCFL, LCD etc.

All these display types do not exhibit a broadband spectra (which is what most of the colorimeters are profiled against from the manufacturer).

Again, the colorimeter is better at low light, the spectro better at color accuracy (i1Pro gets very funky below 30% light). Professional calibration solutions such as Calman and Chromapure have functionality to profile a colorimeter against a spectro which creates a COMPENSATION PROFILE which will be used throughout the calibration for that specific TV set.

Spectros almost never drift over time, colorimeters do. You can take a very old colorimeter that has drifted a lot, after it’s profiled against a spectro it’s better than new.

anyways, basICColor got back to me, they don’t support it (yet). Eizo got back to me, CN does not support it either (yet)…

Any tips are appreciated…

and btw, regarding color accuracy:

I ran a calibration for my Eizo CG275W in CN for sRGB colorspace with the i1Pro and primary colors in the gamut were closer to reference points than the previous iD3 calibration… obviously low light was an issue with the i1Pro…

my iD3 was built in 2012/04 - my i1Pro was built in 2011/11…

so my very new i1D3 is already off the spectro…

I am aware of the differences between a colorimeter and a spectrometer and why colorimeters are generally more accurate for screen measurements than the aging i1Pro spectro. And the i1Pro definitely is far less accurate than the i1Dpro when it comes to emission measurements, not just in the darker tones, but everywhere. And one has to remember, the 2 devices are measuring completely different aspects of the light entering their apertures.

I’ve no experience with calibrating or profiling anything other than computer screens. Since all TVs these days are functionally equivalent to a computer screen, be they CCFL or LED backlight, they still use the same LCD technology to display the actual image (obviously not including plasma, projection, Laser and other non-LCD TVs).

Therefore, I would have thought there would be no issues using current computer measurement devices, since they’re optimized for the same type of display technology as current TVs.

Regardless of all that, the i1Dpro has an in-built calibration matrix table, specifically to deal with the differing types of screen technologies you mention, so it would seem the manufacturer might already have solved your problem.

Finally, as mentioned previously, the i1Dpro is accurate to within 0.2-0.5dE2000 when compared with the Discus, likely the highest quality, most accurate consumer-level (non-lab grade) colorimeter currently available. This is well and truly below the average person’s level of perception, so is it really worth all the hassle to more than likely get no improvement in accuracy?

okay, this conversation is running in circles… :wink:

color accuracy of the colorimeters WILL drift over time - even the Discus with it’s very well built hardware… and if u got a bad apple from the factory, ur brand new colorimeter is FAR off, right away out of the box…

and u will never know until u profile it against a spectro (which almost never drifts) and u see HOW MUCH ur colorimeter is actually off…

but - again - it doesn’t matter how much it is off, IF (!) you have the ability to create a compensation profile against a spectro… BULLET PROOF solution… that’s why the Pro’s do it that way…

and regarding the Discus - which I love: the Discus is already off the reference points and the iD3 is more off than the Discus… they are both still very accurate… until they lose more and more accuracy… the Discus is definitely though the best affordable colorimeter atm…

So have you tried the Argyll/dispcalGUI method of creating a colorimeter correction matrix? I’m guessing that should be just about exactly the kind of correction file/app to create said file, which you’re looking for. It’s completely free, open source software, so you’ve nothing to lose except your time and hair. :stuck_out_tongue:

hahahaha… well, I’m losing that big time… :wink:))))

I did not look into that yet, I was hoping for basICColor or ColorNavigator integration or post calibration tweaks in any of the two…

Looking into Argyll…

Thanks.

I was asking the SpectraCal folks here in Seattle to comment on this topic since they would know more about this than we do, but I haven’t heard back from them yet. Some of us at CHROMiX got a tour of their facility a few months back - it was quite fascinating. The just about ‘wrote the book’ on TV and video calibration.

Eizo offers a separate app with that comes with some models called the Correlation Utility.app. For these displays like your 275 that have a built-in colorimeter, Eizo provides a way to correlate the measurements of the built-in swing sensor with the measurements of other measurement devices. This is useful in work environments with other Eizo monitors and where one measurement device must be used as a standard for all calibrating. It might not be what you’re looking for since all the displays must be Eizo’s, and it works in conjunction with the swing sensor. BTW you haven’t mentioned that in your devices… are you using the swing sensor on the 275? I have found that sensor to be right up there with the DISCUS in accuracy and black measurement.

Patrick,

I’m assuming by “swing sensor” you mean the built-in (auto calibration) sensor…

The SENSOR CORRELATION functionality is integrated in Color Navigator and accessible from the ADVANCED menu…

Using the built-in sensor for auto calibration (and only for that) is useful - u have to profile (–> correlate) to a reference device, which is your own measurement device (colorimeter or spectro) to the built-in sensor to accommodate for it’s color drift - same idea what I wanna do with the spectro / colorimeter profiling…

I think the built-in calibrations sensor is off limited usability - as Eizo sates itself in it’s user manual. Ur own reference device is already off a bit, they themselves state that the built-in sensor will be even more off (after correlation). It is useful though for auto calibration schedules for the display to stay in good shape until you do your own touch-up with your own reference device, which CN calls VALIDATION (of a previously created TARGET)…

My Eizo contact says they don’t have it and he has never heard about it (he will contact his chief technician) - same thing with basICColor… I have to say I am a little bit stunned… you buy these very expensive screens for one sole purpose: COLOR ACCURACY… not having the option in the software or them even considering the implementation of this obvious, very helpful workflow - which is easy to implement - just really surprises me…

basICColor told me they are more targeted towards “Photographers”… since when is color accuracy not a high priority subject in photography ? :wink:

Yes, a lot of people just assume these instruments are 100% accurate. To get that level of accuracy you’d need to have a spectroradiometer ($20,000). My understanding is that the lowly colorimeters work so well for the average photographer because in addition to a fair degree of accuracy they offer repeatability. It’s important to bring a display back to a known state, month after month, so that the basic color appearance does not change. Even if that state is not 100% accurate, it still allows a photographer to know what’s in the image, see shadow detail, have the display match what comes out of the printer. I talked a little about this in one of our newsletter articles - on the DISCUS in fact:
colorwiki.com/wiki/DISCUS_Review

There are even problems with the i1Pro spectro. We participated in an IDEAlliance SWOP proof study a few years ago that included a study of measurement instruments. The i1Pro’s that were used were off from the accurate bench reference device by as much as dE 1.20 - and were inconsistent from reading to reading by a standard deviation of 1.25 within the same instrument. These had to do with reflective measurements. I don’t have any stats specifically for emissive measurements.

All of this seems to bolster the case for getting good instruments. There is enough variation in our instruments that end up being visible to the human eye, that adding the variation of the display you’re measuring, the environment, etc. - it all adds up to the point where you could doubt you’re seeing your color accurately. On the other hand, in practical everyday usage - many people calibrate & profile their displays and get results they are very happy with, that saves them a lot of reprints and allows them to get their work done pretty well. So I don’t know. I guess there are both kinds of people in the world.

I’m not sure where exactly you’re getting your info from but it is actually quite incorrect, or perhaps you’ve just misunderstood how the built-in Swing sensor is to be used and what exactly the correlation utility does and how it is intended to be used. I’ll try to elaborate a little…

Firstly, the Swing sensor is SO much more accurate than either an i1Pro or i1D3, to the point that if the Swing sensor is correlated to either device just mentioned, the overall accuracy of the Swing sensor would be reduced substantially. One has to remember that Eizo checks, calibrates and correlates EVERY screen which has a Swing sensor, to the Lab-grade CS-1000A spectroradiometer (list is $25,000, very easily in excess of $30-$35,000 with a couple options). And that was from a couple years ago, when the Swing sensor screens were first released. I’d be very surprised to find out that Eizo would not have upgraded their in-house/factory Lab-grade Reference device to the newer CS-2000, which lists at some places for a bit over $45,000!!!

So, even blind-Freddy could see that there is simply no possible way that anyone could ever use an i1Pro or similar priced device to do anything to the Swing sensor except to destroy its accuracy.

Regarding the long-term drift of the Swing, again, it has been documented that the Swing is MUCH more stable and accurate over the long-term than any consumer spectro/colorimeter device (in normal humidity conditions) and if being used in high humidity, the Swing is approx. 700% more stable and accurate over the long-term(!!!).

Here, you’ve completely misunderstood everything about the Swing sensor if you think it is of limited use/useability. It is supremely accurate because it has been factory correlated to a $25-$40,000 device before leaving the factory, so quite obviously, if correlating the Swing to one’s own device with substantially lower the accuracvy of the Swing (unless you own a $25-$40,000 Lab-grade device with which to correlate the Swing).

Regarding Validation, this is absolutely nothing whatsoever to do with ANY kind of “touch-up with your own reference device”. It is purely to be used for Validating the profile/calibration of one’s screen and to give the user an idea of whether or not they need to re-calibrate/re-profile and if so, then how often it should be done. The Validation simply tells the user how far off their current measurements are from those made when the profile was first created or updated (to see if the screen itself has drifted since last calibrating/profiling).

Where exactly are you getting this infd about the i1D3 being such an inaccurate device? Red River has documented in their testing that the i1Pro is SUBSTANTIALLY less accurate than the i1D3 for screen measurements. And that was made by using about 10 i1D3 devices and 12 (I think) i1Pro devices, not just 1 or 2 of each device.

You should most definitely read both Eizo’s own White Paper anbout the built-in Swing sensor and also Red River’s testing of the various consumer screen measurements devices currently available.

I know you will then be absolutely amazed at how accurate and repeatable the Swing is and even the i1D3 both sare, when either device is compared with an i1Pro.

regarding the swing: my Eizo contact said to correlate it to the i1D3 - if the swing was that accurate it should be the default and only meter used on this screen - EVER - for every calibration and everything else… seems odd that CN software expects you to bring in your own inferior meter to do a calibration when you have that device on board… but, great info, I’ll check back with my Eizo contact… thanks.

u have to differentiate between measurement variations between individual units and off-values to a measurement target, e.g. color primaries of a given color space - again a colorimeter will only be accurate for certain screen types (light sources), and less for others - it’s the nature of the device

again, not sure what the point is to repeat over and over that u don’t know how accurate ur 1iD3 is (mine had a noticeable, slight red push), until u profile it - and even if it (hopefully) is accurate (being a new device), it will drift at one point

anyways, here’s the good stuff:

checked out Argyll CMS a little bit over the weekend, amazing piece of software… MUCH more powerful than basICColor IMO… man, this baby is fantastic

not only can you correct a colorimeter to a spectro, there are so many fantastic, in-depth options, it is now possible to run a much more thorough calibration (resulting in a better profile)…

on my laptop (which was prior to that calibrated with just the i1D3 and basICColor), I ran a calibration profile with just the i1D3 and then with the i1D3 corrected to the i1Pro - the latter is dead on and the difference (to the first calibration attempt) is plain noticeable (when switching between profiles)… delta E’s were good before, but never that low on this screen…

and again: my i1Pro is new from 2011-11 and my i1D3 is new from 2012-04… and it is OFF a (little) bit…

and btw, Argyll CMS is connected to an online database where users all over the world upload their correction matrix of a given colorimeter / spectro combination on a given screen, so other users (who don’t have a spectro) can make use of that… now I’m not saying that this will be as accurate on somebody else’s (identical) screen model (given the possible variations in the display units itself), but guess why they all do this process (profiling colorimeters) ??? BECAUSE IT IS MORE ACCURATE. :smiley: