Upgrade to EyeOne Display 3 PRO w/ ChromaPure? - Page 2

Hi all,

With the PRO version, are these corrections hardcoded(flashed) in the unit or entered in the Meter Correction fields in the Chromapure software?

Thanks!

Thanks for your prompt reply. My i1 Display 3 PRO is on its way and have received the cailbration report and the license file.

I can't wait to try it out on my Pioneer LX609A. Not sure if this is the equivalent of the Elite panes in the US. The only difference I think it has is the omission of the PURE mode.

I would be interested to see if someone can supply a report on the PURE mode settings. Just curious!

Thanks,

If I'm interpreting this correctly, ChromaPure makes one correction for front projectors facing the screen, regardless of technology of the projector. Is this correct? I ask because CalMAN makes several corrections depending on technology used in the case of their C6. For front projectors facing the screen CalMAN has 5 selections: CRT, UHP, Sync enabled UHP, White LED, and RGB LED. I have tried all these with my MICO 50 (RGB LED) and the RGB LED selection gives the best grayscale, at least judging by eye, and is significantly different from the CRT and UHP selections which give results very close to each other. Maybe this is a reason the C6 costs more?

Once the light reflects off the screen, the screen itself becomes the dominant variable in the measured value. When reading self-luminous displays or projectors in illuminance mode, the light source is the dominant factor.

If that's the case, why does Spectracal have 5 different calibration tables for measuring off the screen? The modes vary by the technology of the light source. I guess that's a question for Spectracal to answer.

To support the community I felt it necessary to put out this statement of facts.

Fact 1: The D3 based meters be it the OEM, C6 or Retail are not calibrated by X-Rite in the traditional way of a four color matrix. The new method X-Rite has devised gives you a much more accurate meter and less meter to meter differences.

Fact 2: The SpectraCal lab is the only calibration laboratory outside X-Rite that has the tools and has been authorized by X-Rite to properly add additional display spectral responses to the D3 platform. SpectraCal is under NDA with X-Rite, so we can't go into detail on how this is done.

Fact 3: The SpectraCal C6 is currently the only D3 based meter that can be field upgraded using the authorized method by X-Rite to support additional display spectral responses. We just added RGBY LED direct view and will be adding Xenon projector lamps. Field upgrade means you don't need to send your meter to us. The additional calibration tables are added with each updated version of CalMAN.

Fact 4: With front projector calibration the screen has minimal effect on the chromaticity. The better screen manufacturers spend a lot of time and effort to make sure the screen does nothing to the spectral response. SpectraCal labs have spent a lot of time with various screen manufacturers to make sure of this. For those screens that do have a chromaticity shift it is a constant and does not change with different light sources. See spectral responses from a UHP and White LED projector, they are very different no matter what your screen is.

Fact 5: With five different types of front projection light engine designs you need that many tables added to the D3 based meter for the most accurate response (UHP, Xenon, LED White, LED RGB and Laser). The SpectraCal C6 has UHP, LED White and LED RGB. We will be adding others in the future.

Yes if you were using the traditional four color matrix correction but with the approved processes from X-Rite it is not a factor.

Derek,
I may have missed this, but is the retail meter upgradeable to C6?

Fact: Display calibration is not a medieval theology with mysterious formulas and magical methods. It is an entirely empirical effort. Methods work only as well as the direct evidence shows. In absence of any actual data--or in this case even any rudimentary explanation of the method being used to derive the data--any claims about better or "more accurate" performance cannot be taken seriously except as an exercise in marketing.

Fact: There is no method, real or imagined, that can compensate for the variations in individual meters short of actually testing a meter's performance and applying a correction to THAT meter.

Fact: The four-color matrix method of correction as described and used by NIST and many others has been the industry standard for years. There is voluminous data on how well it works, which is very well with errors typically below the threshold of visibility.

It would be interesting to test this or any other method of correction against any new method and compare the relative merit of each, but alas one of the comparators is apparently secret and proprietary.

To serve the community, I would ask that consumers make a reasonable effort to distinguish between claims about video calibration that are open to testing and analysis and those that are offered as articles of faith. Your choice.

I don’t think I would challenge X-Rite and all of their color scientists including some of the original design team from Sequel Imaging. Whom by the way were one of the first to design a portable tristimulus colorimeter. I think they know what they are talking about and should be given some credit for the millions in research to come up with new designs. The D3 family design allows for a meter to be characterized at a much fine detail than ever before. But to take advantage of this new design they need to be calibrate a new way.

So here is the interesting part and one of the reasons I posted on this thread in the first place. A statement was made that a tristimulus colorimeter only needs a single calibration table for front projectors because of the screen being the dominate factor. Well I very much and openly challenge that statement because color science dictates it is simply not true. It is a very simple experiment anyone with a spectro can perform. Shoot the spectral response data for several front projector light engines types on the same screen and you will see they are not the same. Therefore you need a calibration for each major light engine type. This is no different than needing a calibration table for LCD CCFL vs. Plasma. They both use phosphor to create light and are driven with RGB data but the spectral response is different.

No the C6 has different firmware that is loaded at the factory. We will however take your D3 OEM, Retail or any other version in on a lucrative trade for a C6 contact Josh or Alex and they can get you sorted.

I sit completely on the other side of the fence as I own a RGB LED driven DLP projector. I'm quite confident the C-6 will measure my RGB LED driven MICO 50 much more accurately than the D3 Pro when facing the screen. The D3 Pro has only one calibration for any front projector and that calibration is not for a LED driven projector. I would like to see Tom show some proof that a single calibration will suffice for these different spectra projectors, and I don't think it can be done. Consequently, I stand firmly with Spectracal for front projector calibrations, and for a few other reasons that are not pertinent to this discussion.

I calibrated a Vango LED PJ a few months ago, taking readings off the screen from my reference instrument and then with the colorimeter I was using (I think it was the Klein K-10). As I recall, the corrections were quite small, typical for the corrections I have seen when calibrating many other FPs (UHP), which is to say that the LED light source made little, if any, difference to the corrections required.

However, memory is flawed, I didn't save the necessary data, and I wasn't using the D3 in any case, so I have nothing concrete to share.

As I indicated, this is not about belief, faith, or theory. It is about empirical evidence. The next time I measure a LED PJ off the screen, I'll be happy to post how well the D3 PRO's Front Projector mode matches the reference data.

Of course they are similar the C6 is based on the OEM D3. But the main reason the C6 costs more is what we do to make sure you get the most performance out of each one we sell. The equipment required to calibrate one and the reference displays needed are a significant cost. The time required to certify to NIST standards and maintain a NIST lab are also a significant cost. If I were a Pro using a meter I would like to know everything possible has been done to get the best performance and have cert's to prove it was done.

Well I guess we have it then. The statement that was made that a person only needs a single table for front projection was not based on fact or evidence but a failed memory on a meter that was not even the same as the D3. This is really surprising. In our calibration lab we jokingly call this the just good enough syndrome. Well if it was close and I think no one can tell maybe than it is just good enough.

I can tell all of you we spend a significant amount of time in our research lab testing every display type and meter before it even is certified for us to sell. This does not come cheap but when we put a NIST cert on something we have to stand behind our test methods and procedures.

SpectraCal is going to do something we have never done in the past and that is publish data on this matter to put it to rest. Our lab is backed logged with the new K-10 Cinema Pro, Discus and C6's so it maybe a few days before I post on this thread again.

Just Good Enough does not cut it n our world. Our customers have come to expect that from us and rightly so.

I am a DIY calibrator getting excellent results from an Xrite D2 Lite.

What benefit would the super accuracy give me on my LCD TV?

I can understand photographic uses needing this but surely TV and other video by its very design is a series of algorithms and manipulations of the human eyes vulnerabilities?

I feel that for TV use we are arguing about a micrometer readout when a tape measure would be adequate.

For photography we have a constant to measure. Is this the case with the average display which has many variables giving an almost dynamic output?

You are quite right I don't know but I am satisfied my PQ is excellent.
I am happy that I get reproduceable results that are verified technically by my software and PQ.
No green or red (or any other color ) of tint in the grayscale.

Perhaps I am lucky with my D2 and I have got one that actually works?

Regarding your perceived '...clearly visible improvements....', how do you know they are improvements?

Perhaps your D2 was not as good as mine after all they do vary don't they?

Interesting thread for someone considering to buy the upgraded (reference profiled) meters vs the standard ones.

We have debating that there is a difference in accuracy, on average, between a standard D3 from the factory and a reference profiled one, although exactly how much difference the reference profiled one will make will depend on how lucky/unlucky you are with your factory D3 tolerance, and to a certain extent how fussy you are with color accuracy. But it looks like the pro/C6 versions could calibrate a better looking picture.

There is also debate about needing different reference tables for different display bulb technologies, but for someone using these meters to calibrate a UHP projector the Chromapure approach should be sufficient as Tom uses the reference profile from a UHP projector. If you want to calibrate multiple display technologies the C6 may have the edge (still being debated) at a higher pricepoint due to the extra profiling work needed.

Is my above summary of this thread correct?

What about meter drift?

Previously I had to throw out a D2 because it drifted so much, so am wondering about how to compensate for the drift over time without having to send in the meter for recalibration against a reference meter. Assuming a new meter is pretty accurate (eg. the D4 Pro), would it be possible to take readings from a new meter against a white tile, then for the next calibration (eg. 6 months later) take another reading from the same white tile and use the differences to build an offset table for the meter to compensate for drift? If you are careful with the tile & the light source, shouldn't this be an accurate way of compensating for meter drift, and save cost/hassle of sending in the meter?

You know, the more I think about this the more I think that this debate is misplaced. Whether tristims require a specific LED correction for reading off the screen is largely beside the point because, as I acknowledged at least by inference in my initial post on the subject, they probably do require different corrections for readings from the lens. In as much as the D3's great diffuser led us to offer UHP FP corrections for both lens and screen, I think we probably need an LED correction for the lens mode, and if we do that it would be silly to not offer an LED screen correction as well.

I'll do some testing on this and report back. If I find that the D3 measures LED light sources significantly differently, then we will add LED modes.

Well here we have it a LED RGB projector calibrated to D65 with our CS-2000 and then measured with a C6 using the LED RGB table and again with the UHP table. The chart below is a 20-100% grayscale run.


The differences are enough that if the LED RGB projector was calibrated using a UHP table it would be visible. In this case it would have to much green overall.


Spectral sweep of a LED RGB projector and a UHP to show just how much difference there is. This was done reading off of a screen.