One Of Two[/b] Summary Reports of Mr Stephen Withers’s calibration on Saturday 27th July 2013
As well as actually doing the calibrations, Stephen has sent me detailed reports on each television. I’ll HEAVILY edit the first set of reports and show only the Gamut CIE charts and RGB balances for all four televisions, pre-calibration, and then show a post-calibration balance for only one[/b] television (because post-calibration, they all look very similar).
The axes on the Gamut CIE (International Commission on Illumination) charts are the responses of the short-wavelength (letter s ), middle-wavelength (M) and long-wavelength (L) cones in the human eye. (Anyone wanting a simple but sufficient explanation of cones and rods photoreceptors can check this link
http://faculty.washington.edu/chudler/retina.html .) You will see that the Gamut CIE graph has seven small squares and seven small circles. If I’ve understood that nice Mr Withers correctly, the seven squares are where the seven colours (red, green, blue, cyan, magenta and yellow - and White?) of the television being tested SHOULD measure on the chart. The seven circles are where the colours, pre-calibration, in fact measure on the chart. One purpose of calibration is to bring the circles inside the squares, so that the seven colours do in fact measure where they should.
In the RGB balances, the vertical axis is just percentage and the horizontal axis uses a unit called IRE (Institute of Radio Engineers) which measures from black (zero) to white (100). The idea is that the Red, Green and Blue responses should all measure 100% at all values of IRE. Clearly, pre-calibration, none of the televisions are 100% for the three primary colours at various values of IRE.
Enough explanation already! This is the PRE-calibration Gamut CIE chart and RGB balance for the Pioneer PDP-LX5090 in the second bedroom.
http://img51.imageshack.us/img51/3967/8een.jpg
See how green is pretty close to 100% at all values of IRE, red is consistent at about 110% and blue is about 87%. This is the Pioneer Kuro, and I mention this because we’ll see that other televisions are not nearly as consistent in going across various values of IRE. Oh, in the Gamut CIE chart, the circles are pretty close to the target squares.
And now the Pre-calibration graphs for the Pioneer PDP-428XD in my bedroom
http://img28.imageshack.us/img28/74/49jw.jpg
This is also pretty consistent as we go from 10 to 100 IRE, but blue is well above 110% throughout, and red is around 93% and green is around 90%. On the Gamut CIE chart, the circles are a bit further away from the target squares than on the 50” Pioneer.
Now for the Samsung PS64D8000 in the parlour
http://img443.imageshack.us/img443/9443/fl76.jpg
This is even more blue-biased than the Pioneer PDP-428XD! In fact, the vertical scale goes up to only 120%, and the Samsung’s blue response is measuring off the scale! Also green at 20 and 30 IRE are struggling to show above 80%. The circles on the Gamut CIE are slightly closer to the target squares than on the 42” Pioneer.
Lastly, the Pre-calibration graphs for my much-maligned LG 60PZ950T in the kitchen
http://img442.imageshack.us/img442/204/i2bs.jpg
Annoyingly, although the strengths of the RGB components vary relative to each other across various IRE values, overall all the components are the consistently closest to 100% of all the televisions, even better than the Pioneer PDP-LX5090. And the Gamut CIE graph shows that the circles are at least as close to the target squares as those of the 50” Pioneer, which is still regarded as a reference device. How can the much-maligned LG 60PZ950T be measuring at least as well, on the pre-calibration RGB graphs and the Gamut CIE chart, as the revered Pioneer PDP- LX5090??? Damn!!
And now a Post[/b]-calibration graph. As the Post-calibration graphs are all very similar for all the televisions, there is no point in showing four graphs, so I give only one, that of the much-maligned LG 60PZ950T television. It can be easily compared to its pre-calibration version immediately above:
http://img15.imageshack.us/img15/4163/qcrb.jpg
On the Gamut CIE chart, the circles are now all inside their target squares, and on the RGB balance, the RGB components are now very close to 100% for all values of IRE from 20% to 100%. Well done, Mr Stephen Withers!
I had meant to do both reports tonight, but this one has taken me 90 minutes, and I’ve had enough! I’m out tomorrow night, so I’ll do the second and last report on Friday night. Now I’m off to the kitchen to play my Blu-Ray of either The Grey or Argo on the 8.1 speaker system based on the Eltax Shine speakers, Calvados finish
http://www.eltax.com/en/model/222_Shine-5-pack.html and that much-maligned LG 60PZ950T television (which looks better, especially for Blu-Ray playback, than pre-calibration, thanks to Stephen!)