The Official ChromaPure thread - Page 5

It's the same with color. Again, I haven't tested this, it is just my general impression.


No, we decided not to try and handle this with software, but rather rely on a hardware solution as I described previously. We do offer averaging, but it applies to all readings, not just dark ones.

I've been noticing all the TVs in the house have the same attribute - as the time that they are on increases, the colours get better! WHY does it take a solid state device so long to WARM up, and WHY do the calibration settings continue to change the longer the TV is on? At what point do the electronics or LEDs finally settle in to a stabilized state? Is it actually the meter that is changing, or the TV system? How can one properly calibrate a system if the values are constantly changing? Calibrating my system has become increasingly frustrating due to these problems. I have flatlined the Green; come back on hour later to find the settings have to be redone - and this is only working with the Green. Given up trying the Blue and Red. Even flatlining the Green, I only go one step ahead at a time, then back two, then forward three to the next IRE to keep the line flat. 90 IRE is the worst!

The meter and the TV are both effected by temprature.

Your best bet would be to turn the tv on, put a meter on the TV and then let them sit together for maybe as long as an hour.

Once everything is warmed up, then things should stabalize.

What about calibrating greyscale and gamut with an i1Pro on a 9G KURO? Are there any major down sides, apart from gamma not being read accurately from 20 IRE down (which I wouldn't mind, since I know my gamma to be flat anyway if everything else is properly calibrated)?

None. If you are not concerned about low-light performance, then the i1Pro is an excellent device-fast and reasonably accurate.

Thanks for your answer, Tom In what cases is low-light sensitivity a critical factor?

Contrast, gamma, and even the bottom end of the grayscale.

http://www.avsforum.com/avs-vb/showt...150014&page=90 #2700

Will try this tonight and post the results - cold start - 1 hour - 2 hour - 3 hour. If you check my post listed above, the values continue to change every hour. 7.5 hours to get back to the previous nights calibration results!

My biggest concern and the reason I've not upgraded yet (from HCFR and i1) is the useable life of all filter-based colorimeters. I've yet to see any life data on these meters and for me it would not be worth the investment if the filters degrade after only a few years. I did ask X-Rite but got no answer. So I'm curious if using the i1 Pro as a reference can effectively increase the life of the filter-based meter even if the filters have started to degrade ? It's seems reasonable assuming a meter offset is run on a more frequent basis.

Has anyone come across published data on meter life, of any type ? It would seem that the filter-based meters are the only type that would have a limited life, while other meters would probably just require re-calibration every now and then.

The filters change as a function of humidity present in the environment where the instrument is used/stored. If you live in Death Valley,CA where the humidity is essentially nil then the filters will remain like new for years to come. If you live in New Orleans, LA where the humidity is very high then the filters which are hydroscopic (absorb moisture) as they are made of schott glass and are built in stacks of several different pieces of glass absorbing moisture at different rates over time then the instrument will require a re-certification every twelve to eighteen months (approximately)

Your assessment of the spectroradiometer only requiring a recalibration vs the filter based analyzer is not correct. Both instruments after a calibration will provide accurate data for the light source which they were calibrated to as a reference. The filter based analyzer does not become useless after moisture has been absorbed into the filters this is simply what causes the drift or deviation from the calibration.

The data which you are looking for would be different for each manufacturers filter based instrument as the filter materials are not identical in each case. The humidity level in the users environment is also a variable which may not be predicted so again it would be quite difficult to provide this information.

I suppose one could provide a graph showing the change of accuracy of an instrument exposed to a constant percentage of humidity and tested for accuracy at specified intervals. This is not something that you will find available for a meter which is considered to be "low cost" by manufacturers.

So long as you have a reference you can use to correct the colorimeter, then this is not a problem. As the filter-based device degrades, the correction will just become larger. (BTW, although real, the degradation is modest, not enormous) Also, the "investment" is very small. i1 LT's can be had for $129. Even if you bought a new one every couple of years, it would be more than 10 years before you had invested as much money as you did in the single i1Pro.

BTW, I just noticed that the passage you cited has a typo. I meant to say "Both the Display 2 and the Chroma 5 are reasonably accurate for luminance down to below 0.05 cd/m2."

What about offering a service to determine the accuracy and provide offsets for an i1 LT? It seems like it would be a worthwhile endeavor for a lot of parties on this forum. Many of us are not in a position to purchase an i1 pro, Chroma 5, K-10 or other more accurate device. Does ChromaPure offer that service?

This is something we have considered. No decision has yet been made, but I think that this is something we would be more likely to do with the Chroma 5. Its expense falls about half way in between the i1Pro and Display 2 and was developed and marketed as a premium, yet affordable, colorimeter for which such a premium service would make more sense.

An alternative approach might be to support those folks that rent an i1p by offering a special "profile" license as it were. This would seem to be particularly useful to home users that want to profile their "lesser" meter on their display.

I second that idea. I don't know how long it takes to profile a meter and provide a correction matrix but if this were an option when ordering I would have seriously considered it. Perhaps this is too display dependent though??

I like the idea of a profile license. I don't know how easily ChromaPure could be modified to allow it to read i1Pro data just for profiling (and nothing else) but this seems like a reasonable idea (assuming a SW mod is reasonable). In my case I already owned an i1Pro but bought a CP/C5 package. I could use HCFR to take i1 Pro readings and then enter that data into CP to use as a reference but this is time consuming and subject to human error. OTOH, requiring a $100 licensing fee to just use the i1Pro for profiling is somewhat steep.

BTW, whereabouts along the Niagara Frontier are you located?

I was thinking more along the lines of the folks that rent (I know of only two) would contact ChromaPure and provide the serial numbers. The license wouldn't limit what you could do and it wouldn't be cheaper (it might be more) but the assumption would be you'd only have that meter for a week. It's administrative overhead not programming.

Middleport is the closest village (about two miles away).

I doubt that i1Pro readings would meaningfully improve upon a Chroma 5, especially a relatively new one.

Yes, you convinced me prior to selling me the C5....and that is why I did not do that (especially with a 7 year old i1Pro).

Gotcha.

But there are a lot of valid and understandable arguments to be made for profiling which means two licenses if one does not wish to do it manually (as I suggested using HCFR). I believe Calman also requires two licenses if one were to profile a colorimeter with a spectro.

SpectraCal has a variety of licenses so one interpretation of your example might require one, two or even three. I believe ChromaPure is fairly consistent in one license per serial number while SpectraCal has classes which sometimes have non-obvious occupancy rules.

If you are going to create your own profiles, your best bet is the "Enthusiast" license. If you want to simply use a profile, any license will do, but someone will need to create it for you. Yes, you can bundle several Home licenses together, but that was why we created the Enthusiast license in the first place.

Tom,

Would you suggest setting up the Display 2/i1 Pro offset in Chromapure with the 100% or 75% window patterns? The reason I ask is I used the 75% patterns from the AVS disc and have the following charts. Chart 1 is from the Display 2 as the field meter referencing the i1 Pro. Chart 2 is the i1 Pro alone. One can clearly see the low light ability of the Display 2 over the i1 Pro. Do these results look as expected?




I keep playing with the calibration on my G10, but do not think I am going to get it any better. I keep calibrating the gray scale in Custom, then THX just to do it. I need to find some people with local TV's that need tweaking!

Lastly, is there a way to "export" the charts like you can the images with Chromapure? I find the cleanliness of the x,y,Y,DE,CCT,Gamma gray scale values or x,y,Y,DE color values from wtihin the program more desirable to post than an excel .csv file. Maybe add the ablitily to export these as jpgs? Just some food for thought...

I don't think that it is critical. All else being equal 100% is better because you get more light output. But all else is rarely equal and displays are sometimes non-linear at 100%. I use both, but for a plasma I would think 75% would be fine.


Yes, you can export the report data and charts either as pdf or xls.

Hi Tom,

Two questions for you

1) I have an older DTP-94 that came with the MonacoXR software for LCD monitor calibration. I am having no luck in getting this meter to work with Windows 7 x64. The only solution I've found is to run Win XP as a guest OS in virtual PC. Since this meter is nearly 3-4 years old now, I think it's about time I look for a new one. Does Chromapure work with Win7 64bit and have you any recommendations for meters that have native x64 drivers?

2) I noticed that your upgrade policy is slightly less forgiving than Calman's in that you only offer free upgrades based on point releases rather than how stale the license is. For this reason I was wondering if you plan on releasing a new major-version number within the next 3 months or so?

Thanks.

Yes, we have a version that works in 64-bit Windows 7 with the DTP-94.


We don't plan on releasing a full point upgrade for some time. If I had to guess I would say late Summer, early Fall.

Can someone suggest to me a basic calibration setup for a first-time newbie that wants something to calibrate my projectors?

So I need a "home priced" colorimeter, some software.
What else might I need, what about if I want to take custom contrast ratio measurements, any special equipment needed here?

I like this idea too. My ideal package would be the i1 Pro with Chroma5, using the i1 Pro to create an offset... BUT it almost seems silly to buy the more expensive i1 Pro and then only use it as a reference. Throw in the fact that the i1 Pro should be calibrated every year or two and it starts to become a fairly expensive solution for a home user. If the cost of renting an i1 Pro is less than the cost of calibrating the meter (and assuming the lessor company is properly maintaining and calibrating their i1 Pro's), I think the decision to rent is a no-brainer.

So Tom... is there any chance that ChromaPure would allow for an open (not tied to a serial #) i1 Pro license ?

You don't need a license to use a reference device. Just enter the xy data manually. It takes about a minute. I do it all the time, because we haven't gotten around to adding support for our reference spectro yet. Also, using the i1Pro as a reference to correct a Chroma 5 would not be a good idea. The Chroma 5, especially a relatively new one, offers nearly the same accuracy as an i1Pro.

What is the least amount I can spend to get everything I need to calibrate my projector (doesn't have to be perfect, just best bang for the buck type thing). Any recommendations?