Calman vs Chromapure - Page 2

I am referring to the OEM i1 Display Pro, I'm not sure where the Pro went on our website, but I am referring to the OEM version of the meter x-rite sells as the i1 Display Pro.

I typically try not to talk specifically about competitors products.

Then without talking about competitor's products, there is nothing in the statements about the C6 that indicates it is any more accurate than the OEM i1 Display Pro that has been calibrated against a reference meter for a display by the user with those tables being held in the software versus uploaded to the C6. All of you statements only talked about the stock OEM tables and not an individual reference calibrated OEM meter.

There is some confusion about nomenclature.

The official X-Rite name for this meter is the i1 Display Pro III. They leave the III off sometimes, but it is on the retail packaging and it is included in the internal name.

In the past we have distinguished our standard meters from our individually calibrated versions by using a PRO suffix. I didn't think we could call our calibrated version of this meter the i1 Display Pro III PRO, so we simply call the standard version Display 3 and the calibrated version the Display 3 PRO.

Sorry, perhaps it's just me being a home DIY enthusiast as opposed to a professional, but it just feels to me like there is a bit too much snake oil going around. This just fuels consumer mistrust and confusion.

I bought Spectracal's OEM i1Display since I currently own Calman and a ColorMunki. I am still puzzled at how this meter is intentionally crippled by Calman. Could someone please explain? The program default is set to 1 second. There are definitely times that reading times are 2 seconds. There are even times when reading times are around 4 seconds. For example when measuring a white IRE 109% window with backlight turned down constantly causes around 4 seconds per reading. I thought that this meter was suppose to be faster?

How does ChromaPure's speed compare with the same meter? Has anyone done a direct comparison?

I am just going to give up. The OEM calibrated meters sold by Chromapure and Spectracal are more accurate than the OEM uncalibrated. That is clear. They are calibrated by using calibrated reference quality meters traceable by the calibrator of the reference meter to NIST. Different display types are measured with the reference meter and the OEM meter and corrections are either entered into software or stored physically in the meter itself depending. Whether there is any difference in the accuracy of the calibrated meter sold by either manufacture is not clear. Though one comes with a NIST certificate directly applicable to it and not the reference meter it was calibrated against. Neither manufacturer specifies the accuracy of the calibrated meter against the uncalibrated meter. It has not yet been discussed whether getting the NIST certificate means that meter has to be meet some specified accuracy standard. Like NIST sets the standards and if they are met, bingo your meter is individually certified because it meets the standard. But obviously, if ones meter is offset to read at calibration time identically as the reference NIST traceable caibrated reference meter . . . . Yikes. I still don't know. What about the other points. The damn meters do not read linearly at all levels being measured. Is one better than the other in this regard? Does NIST certification mean it is more likely to?

The calibrated version sold by Spectracal is substantially faster than the uncalibrated version sold by them. Why? For whatever reasons, we don't know, and can only come up with nasty marketing reasons.

Whether Chromapure Display 3 Pro or the Spectracal C6, is faster than the other is really unanswereable because each only runs with its own company's software and thus must be considered as a package and thus I suspect the software is the controlling speed factor. But WTF do I really know. They are both fast and fast enough for me. But a pro calibrater may really feel the need to buy the faster one. Time is money and minutes saved on a job can add up.

Which package is faster? Someone else can answer. I really don't care if an auto cal takes a minute or two longer on one vs the other.

And then we have the NIST certifcate which despite being the legislative drafter of the legislation which provides the enabling authority for NIST to perform its functions and renamed the National Bureau of Standards as the National Institute for Standards and Technology I still don't have a clue as to what I get by getting one with a NIST certificate. To me all I care about is which one one calibrated by CP or Spectracal, is likely to be more accurate, And I still don't know but I suspect even if I could find out, their accuracies will be about the same. Once I get down to the less than de 1.7 level, I really don't care.

Obviously I am still confused but I am blaiming only myself for not being able to understand the answers being provided me. Bourbon. I need bourbon and then I have to up early tomorrow to pack and go to the airport for Cedia time.

Spectracal does state that some accuracy would be sacrificed at the fastest setting. So they did choose 1 second as minimum.

Calmans version of the EODIS3.

OEM: fixed exposure time from 1 to 4 seconds (that's per sample!)
C6: adaptive exposure time starting with 100ms

Regarding overall speed. And as you can see in this video from chromapure it can take a loooong time to get an accurate value with the EODIS3 at IRE 10.

http://www.chromapure.com//bugtest/10/10percent.html

So what is better a fast unreliable value or a reliable but slower value?

Must be a trick question.

Your starting to get there.

Accuracy of a colorimeter is determined primarly by the reference meter it was calibrated against.

Since even reference meters don't agree as tightly as most people would like a C6 that was calibrated on our version of a white LED with our CS2000 would likely appear less accurate if compared to another meter that was calibrated by a different spectro on a different flavor of white LED if the C6 was on that display being compared to that other spectro. Conversely if you put that other meter on our white LED set and used our CS2000 our meter would appear much more accurate.

When determining accuracy has so many variables, I can understand how it can be frustrating when you simply want a straight answer of which one is more accurate. Given the right condition either could be. I think ours would be often be more accurate in more situations because of the technology we are using.

Then if you go off and calibrate it against an i1 Pro in the field, well it's going to have the accuracy of that i1 Pro. The i1 Pro is a fairly course spectro and I could probably demonstrate a scenario where the C6 was more accurate than the i1 Pro, especially if it was the scenario above, a spikey spectrum LCD that the C6 was calibrated against with the CS2000 against an i1 Pro that was calibrated against a different source than the CS2000 was calibrated on.

The value of the NIST cert is basically what you think the NIST cert is worth. For some not having it would be a deal breaker. It's proof of the accuracy of the meter, probably not for the owner, but for his clients. If you don't have clients than it's just assurance for you that your meter was personally checked and calibrated to it's rated spec.

Thanks Sotti.

Does Calman offer measurement smoothing as in the example above?

Eh? A half second or so for a single read and the video shows the reads repeating beautifully. You can bump the measurement smoothing from 1 to 3 or 5 or 10 whatever, but in the case of this meter and display, why?

What is beautiful from red starting with 111% and ending after 20 seconds at 98,9%? And I would bet letting it run a little bit longer it would end even lower.

So let it run for 2 hours and get it at ) error. BUT The zero is against what the meter measures and that will likely not be correct as the meter ages and given that its accuracy at other than at the the offset point or points given the non linearity of less than reference quality meters. If you measure 0 error, it means really nothing. You might have been closer at point 1.7 DE and going to a true 0 error from an error that was truly 1.7 would be undetectable by ones eyes. If it makes one fell good to have those pretty graphs and charts show, great. But there is litttle likihood that the error is 0.

After thinking about this post a bit and wondering what it is talking about, I think the issue raised was from a different understanding of the demo. Certainly I thought and I believe AV-Freak did also was that there was NO adjusting during the demo so that the repeatability of the meter kind of sucked and that it was changing over time reading the same image so which is it, 112% of 98%? If the image was being adjusted to drive the color to 100% then it was unclear in the demo.

Did the mentioned video get changed? I don't see any significant change in the red?

bob

I'm sorry for asking this in various threads, but I really need an answer on the "crippling"? Has anyone tested a CM OEM D3 against a CP D3 in both softwares to see if there is a major difference in speed, etc?

thx

bob

They are the same meter and perform exactly same regardless of vendor.

The software package that run them are different, so there will be difference is the software handling the meters.

Now that makes sense.

So, you should get the same results with both, just a different way of getting there?


bob

Let me correct some misinformation.

1. The OEM model does NOT have a "fixed exposure time". This confuses the OEM i1 Display 3 Pro with the ColorMunki Display, which is a less expensive and less capable version of this meter.
2. The video at this link http://www.chromapure.com//bugtest/10/10percent.html is not the video the poster is talking about despite being the link referenced. This video, as the path indicates, was one I uploaded to demonstrate some reported issue with a bug the details of which I have forgotten. The poster is referring to this video http://www.chromapure.com/movies/Display3/RGB/rgb.html that was posted 17 months ago as part of the initial release of support for this meter.
3. The Display 3 or Display 3 PRO has no issues with repeatability down to very low light levels under the conditions described. This is for two reasons. First, since initial release, we have continued to refine and improve support for the meter based on the experience gained, and this has improved performance. Second, even if that were not the case, the video leaves a misleading impression because of the type of averaging we use in continuous mode, which samples many readings before reporting a result. The sample taken is larger the lower the reading and the read time is also slower at very low light levels. Taken together this means is that the 10% reading was initially outputting values that were still influenced by the 20% reading taken immediately before. This continued for several seconds until all of the 20% data was purged from the data set leaving only 10% readings to contribute to the reported value. This is clearly not a repeatability problem, which would show itself as random fluctuations. It is a slow and steady reduction in the amount of red reported, because at 10% gray the projector was actually putting out less red than at 20%.

To demonstrate this, I just captured another video.

http://www.chromapure.com/movies/repeatability/repeatability.html

See that the first time 10% is measured, it takes several seconds for the xy values to stabilize. The readings start at x0.309, y0.329 (R96, G101, B101) and then stabilize at x0.314, y0.333 (R99, G101, B97). This is a 4% change unlike the 13% change seen at 10% in the July, 2011 video. The difference is largely due to the improved support I mentioned. The remaining is due to the lingering effects from the previous reading. Again, this is not a repeatability issue. It is just the time lag the system requires to purge the data from the 20% reading. When I close the module and then reopen, thereby purging all of the data, and then measure 10% again, it goes to x0.314, y0.333 (R99, G101, B97) immediately with virtually no fluctuation. You'll also notice that when continuous readings start for the first time at 30%, it takes about 5 seconds for them to settle down. This is normal.

I also took single readings at 20% and 10%, which eliminates the averaging present in continuous readings, using a flat panel. This is probably the best test of repeatability.

http://www.chromapure.com/movies/single/single.html

Regarding speed, I posted an updated video on this as well. The Display 3 is a little slower in ChromaPure than it was at initial release, again because of our refined support, but it is still quite fast, completing a 10% grayscale run in about 13 seconds.

http://www.chromapure.com/movies/speedtest/speed.html

Finally, this performance is what you see for projectors and LCD flat panels. It is not quite as good with plasmas. To get good repeatability taking single readings on a plasma below 20% you really need to use Measurement Smoothing. Continuous readings perform about the same--the built-in averaging smoothes out the rough edges. Also, plasma read times are a little slower. The grayscale run takes about 22 seconds.