QUOTE(pierreye @ Oct 13 2011, 09:38 AM)
Anfieldude, need your advice on taking measurement for Plasma TV using off screen method. I read in other forum that mention the dark calibration for every few minutes for i1Pro is due to the temperature fluatuation. I'm thinking to put the probe on a tripod 6 inches from the screen and mod a hood to block out ambient light that will cover the probe to the TV. As plasma panel is quite hot, if I can further distance the probe from the panel, it should not drift too fast.
Also there is another issue with i1Pro too near to plasma panel. I think the FOV is too narrow and for low light reading, the sub pixel dithering might cause inconsistency in the reading. I had post in Spectracal forum regarding the distance for i1Pro from the screen to match i1Display Pro 35 degree FOV but haven't got an answer yet.
pierreye,
Its a known issue. That is one of the reasons I profile the K-10 to the i1Pro before the temperature drift occurs and then use the K-10 going forward. I hv done tests on plasmas with the i1Pro on the plasma vs off the plasma. Also a freshly dark level calibrated reading vs a non fresh dark level calibrated one. I also did some repeatibility measurements before on a i1Pro left on plasma for extended periods of time. There were differences in the readings but more in the low end where it is reaching the capability of the i1Pro. The high end is pretty decent but as u know the i1Pro does fluctuate a little as well even in the high end. While the errors are still within 1-2 DE its still annoying. I believe it is due to the nature of refresh of the plasmas (or the LCDs, LED backit LCDs) that gives slightly different readings.
The low end below about 5ft/L starts to jump more and is more accurate after a fresh dark cal.
On my plasma, I did not see too much drift with extended heat as long as I did regular recals. So nowadays, I profile quickly then just check once in a while the profiled K-10 vs the i1Pro. The K-10 checks the refresh rates all the time and the readings are almost always the same meaning the repeatibility is fantastically accurate in both the bright and dark areas.
I also know that the FOV issue is a real issue on the OEM idisplay and the i1pro more so for DLPs, so watch out. There is a UHP sync mode that is better, but I am not sure if it is available during profiling. Another LYN member is working thru some problems on this.
Since u r getting a colorimeter, I would not worry so much for now.
Also, on the i1pro the drifts in colour at 75% and 100% are almost neglible even without the dark cal.
I hope to compare the accuracy of the i1pro vs the jeti 1211 when I get the 1211, but I think the difference will be minimal but the jeti will return extremely repeatable results as it aslo checks and locks the refresh rate before each read. Also the jeti does an internal black read before each read.