New Display 2 PRO and DTP-94 PRO w/ChromaPure

Where did you get that quote from? I can't seem to find it on the ChromaPure site.

http://www.curtpalme.com/ChromaPure_EyeOneDisplay2.shtm

What Tom is doing for us (these 2 meter are exclusive to CurtPalme.com) is the same sort of software-based refinement/expansion of the existing calibration tables as he does with the Chroma 5 PRO. It's in the individualized license file delivered with each unit for use with ChromaPure.

It offers enhanced accuracy across 8 different display types:

Generic LCD
Samsung Standard backlit LCD
Samsung LED backlit LCD
Sony Standard backlit LCD
Sony LED backlit LCD
CRT
Plasma
Front Projection

Give the "What is the Chroma 5 PRO?" section a read on this page.

This same enhancement is what also applies to the EyeOne Display 2 PRO and the DTP-94 PRO.

Note the latter two names with the "PRO" on the end are simply names I made up. I thought they made sense to help differentiate.

As an aside, it also provides a way to recalibrate these lower end meters and save them from the landfills. No need to throw out that EyeOne Display 2 every year or two. Just get it recalibrated.

The EyeOne Display LT can also be done since it's the exact same meter as the Display 2 (just different retail software packaging).

Kal

Ahhh...I see. I bought the Chroma 5 Pro from Tom and am extremely happy with the results. IMHO having customized built in offsets particular to your individual meter to improve accuracy is a no brainer. And the way that Tom integrates the offsets into the license file available in a drop down when you initialize the meter makes usage easy as pie...

Just when I thought I was happy using Chromapure with my Eye One Pro and Display LT... lol

I wonder if there is anyreason to change to any of these packages and sell the eye one Pro to recoop the costs???

It's a fair question. First, understand that without testing several meters and taking an average, I can't give a precise answer to this. The offer just started so I don't yet have a database of corrections to refer to.

Having said that, I just tested one Display 2 (not a new one) on a Samsung LCD and the average error in the x axis was 0.012 and in the y axis 0.008. That's an average--it was higher in some cases, lower in others. Although not scientific, I suspect that this result would be typical for used D2s. New ones, of course, will measure a little better.

I only provide corrections in xy because even inexpensive meters like this do a quite good job of reading luminance.

As Tom mentions it's very much a "it depends" type scenario. When manufacturers give accuracy readings they're typically referring to how repeatable the meter is in continuous reading mode, not how accurately it measures to known standards. They can't do that because the filters start to degrade the moment the meter is manufactured.

The older the meter, the more you'll likely benefit from recalibration. I hate throwing things out knowing that they end up in a landfill somewhere so personally I love the idea of recalibrating even a low end meter like the Display 2/LT yearly. The cost to do so is also about 1/2 of what it would cost to replace. This way you also know exactly how "fresh" it is versus having bought one somewhere else that may have been sitting around for a while on a shelf.


Tom can chime in too but IMHO there's no point in sending your Display LT in to be recalibrated for use with ChromaPure if you have an EyeOne Pro. Just use the 'offset' feature in ChromaPure to recalibrate your LT and you'll compensate for most of the drifting that's happened on your LT over time.

Yes, Tom does use a true 5nm reference spectro to recalibrate (not a 10nm EyeOne Pro) but you're already a step in the right direction by having your own spectro to use to recalibrate your LT before you go to use it.

Kal

Thank you for the honest answer.

Last question in this thread. Does the Eye One Pro do a good job of reading higher luminance levels (say 20 IRE and higher) or does the LT do a better job above 20 IRE (I know it is more reliable under 20 IRE).

Thank you,

Note that 20 IRE is a relative term. It's 20% light output which will be different for every display. A birght direct view LCD may be putting out 2-3 times more light at 20 IRE than (say) a CRT projector.

I typically adjust by jumping between 30 and 80 IRE. IMHO the EyeOne Pro shouldn't have issues at 30 IRE on most average displays with average light output.

It's only when you want to go really low and do a contrast ratio measurement (0 IRE vs 100 IRE) or gamma readings in the low range that the EyeOne Pro has difficulties.

Tom's the pro at this so I'll let him chime in as to where he thinks the useful cut-off occurs with the EyeOne Pro. Remember that it's not a brick wall either.

Generally speaking the EyeOne Pro does everything better than (say) an LT and other consumer grade colorimeters, including lumimance and colour readings (as long as it's able to read of course)!

Kal

I have had enough issues with the i1Pro reading 20% from a front projector (off the screen) that I don't trust it (I do 80-20 for grayscale).

Both meters do an excellent job with relative luminance, which is what's important for color. However, the i1Pro does not perform any better in my experience than the D2 with absolute luminance.

kal


This information is not completely correct! When a manufacturer states the accuracy of the instrument they do so based on a specific light source which is being used. An integrating sphere or reference light source that is NIST certified may be used for example. Repeatability is a separate specification which most manufacturers provide and this is what you are referring to as how the instrument responds during continuous measurements. For certain displays due to power supply stability and other circuitry a displays readings can typically fluctuate within a certain range. To deal with this type of anomaly one needs to use a bit of averaging to reach the desired degree of repeatability.

Filters slowly degrade over time at an unknown rate based on the amount of moisture which they absorb over time. The calibration accuracy will drift as a result of the moisture absorbed in the filter stacks and effect the accuracy of the instrument. NIST traceability recommends re-certification every six months however real world experience tells us you can get 12 months or more out of the instrument if it is kept in a dry environment when it is not used (silica gel dessicant packs in a Pelican Style case). The instrument will certainly drift sooner when used in a humid environment ie South Florida in the Summer vs someone using it in Phoenix, AZ.

Another point to keep in mind is that x,y offset files do not take into account differences in display panel age where the light source varies over time. Using this is similar to sharing calibration settings from someone with the same LCD or Plasma panel. The products were manufactured on different dates and the electronics, glass (panel), and lamps in them vary as well. Over time you will observe differences in the two displays and the correction file will not be as accurate as it once was (if it ever was).

The filter based instruments mentioned in this thread are certified by the manufacturer for Grayscale accuracy only and not for color so using them for CMS adjustments are typically not their forte. A 3X3 matrix calibration which is what the instrument uses internally from the factory is a much more accurate methodology to employ for a specific display. This type of instrument would require a library of 3X3 matrices to be developed for each and every display model which one wishes to calibrate to achieve any degree of accuracy. Without them you are calibrating to an unknown degree of certainty which will certainly be better then nothing however, you do not know in which direction the error is as you rely on the instrument and software to determine this for you!

Oops yes! You are absolutely I confused the two (I shouldn't be reading/posting in 3 threads at once). Sorry for the mix-up!

Kal

This is a myth repeated so often that I have lost count. Decent colorimeters typically do no better nor no worse on average with color than they do with white. True, the biggest errors tend to be with color, especially green. However, the smallest errors are generally with color as well. It is not uncommon for one of these instruments to read red within 0.002 of a reference device. I have verified this again and again. This myth simply will not die.


The only advantage of 3x3 matrix correction is that it applies for the entire spectrum of color, whereas offsets work only for the colors sampled. Since we sample only a few colors in video calibration this is not a problem. Basic "accuracy" is comparable.


"Any degree of accuracy" is a meaningless metric. Obviously, the more closely linked the display used for color correction is to the display being measured, the better the results, with the exact same display being the best choice of all.

TomHuffman


This is not a myth! Simply speak with the developers directly that designed these instruments and ask them if the products are certified for measurement of color! The answer which you will receive is that they are not certified for color. The reason for this is simply that the devices are calibrated to work within a specific colorspace as they are calibrated on CRT/ LCD displays in the lab. The digital display industry currently provides a wide variety of products which use an assortment of lamp types (CCFL, LED, edge Lit, backlit), LCD and plasma panels with very different characteristics for primary colors then the typical CRT displays of a few years ago. When the manufacturer calibrating the instrument uses a specific display technology the best possible results will be obtained by the end user by using the identical display. Using anything else will always provide results which are oftentimes unpredictable and may be quite inaccurate. The instrument cannot be certified accurate for the simple reason that it responds differently to each display technology and each manufacturers displays even when it is brand new and freshly calibrated.

Providing your theory of how the filter based product works only describes part of the issues which calibrators encounter on a frequent basis. Even if you have found that filter based instruments may frequently measure Red to within .002 of a reference device which I find interesting in itself it makes it very difficult to calibrate a display controlling only one primary correctly!


TomHuffman


You apparently do not like my choice of words when I said "one wishes to calibrate to achieve any degree of accuracy". I believe that most people would relate "accuracy" to a calibrated industry reference instrument.





TomHuffman


Is this type of error now commonly considered acceptable with a profiled meter or one using a set of supplied offsets? How much error does the instrument have for a primary in the factory supplied state to know if this is a meaningful improvement?

You should really spend more time and effort actually measuring these devices than focusing on theory and what others have told you.

I now have a database of corrections that I have done for the Chroma 5 large enough to be statistically significant. It includes over 100 readings for 16 different factory-fresh Chroma 5s. This shows both how inaccurate this device is (when new) relative to a known reference and how the average color inaccuracies compare to the inaccuracies of white. Here's what the data shows for 4 different display types.

	White x	White y	Color x	Color y
Plasma	0.003	0.005	0.005	0.005
Sony LCD	0.005	0.003	0.006	0.007
Samsung LCD	0.002	0.005	0.005	0.005
Front Projector	0.004	0.004	0.004	0.005

• Plasma: The errors for white and color are, on average, identical.
• Sony LCD: Color is slightly less accurate, 0.001 in the x axis and 0.004 in the y axis.
• Samsung LED LCD: Again, color is only slightly less accurate in the x axis by 0.003. In the y axis they are identical.
• Front Projector: The errors for color and white are virtually identical.

This data explodes the myth that a tristimulus colorimeter does well with white but poorly with color. This data shows that there is either no difference at all or in some cases only a very small difference. Again, this is for the average color reading. Any individual reading may, and often is, less accurate than white. But the average results are about the same.


I don't think you understood what I wrote. These are the errors [x0.012, y0.008] I measured with an uncorrected Display 2.

Although your limited testing of four displays would show that there is little difference in color accuracy vs Grayscale for the displays tested it is not a large enough sample to make a claim that you have "exploded the myth" regarding these instruments. There is a much larger assortment of display models and technologies to measure which will provide larger deviations then what has been shown in your testing.

The agreement between C5's from the same lot is excellent as they typically perform within .001 for x,y from each other. The test which you performed tells us nothing as to how the instrument performs on a variety of other light sourced displays. Do we now accept color errors of .005 for chromaticity which leaves a degree of uncertainty of .01 -.014 (+/- .005 - .007) which is a fairly loose tolerance.

This test really displays that there is a need for a calibration profile for virtually every display if the user wants to achieve a higher degree of accuracy relative to a reference instrument.

I have a Display2 meter that is about 18 months old. Can I purchase a single license and then send in my Display2 for the Pro upgrade ? If so, is there any disadvantage compared to just purchasing a new meter with the Display2 Pro package ?

I think I would still like to eventually upgrade to the Chroma5. If I were to do so within a year, could I swap out my existing software license from the Display2 to the Chroma5 ?

Sent you a PM.