Originally Posted by mark haflich
Sounds good to me. The problem with many of these cheap probes is the need to calibrate them to the particular system being calibrated. Its not really a question of which probe of the cheap probes is better. The best results will be obtained using an expensive spectralradiometer for the whole sheebang. This is what the pros use and you just can`t obtain the same degree of acccuracy without one to at least correlate your cheap probe to an accurate reading. There are forums on calibration. But the use of expensive equipment is done for a reason. Cheap stuff can get you close but don1t assume that one cheap probe will give better results. It depens and there are many variables.
Manni. Call up someone with a good spectralradiometer and correlate your two probes. then you will get real close.
Thanks Mark, but from my point of view if an i1pro just out of the factory is not to be trusted, then I'm thinking of giving up calibration altogether!
Here is some data from my latest experiments.
1) As Tom remarked, green was too bright in my first attempt. It looks like this was the reason why there was a lack of linearity in my results. Pushing green too high seems to disturb the linearity.
2) I have calibrated with both the i1 pro and the display2 LT, and although they do not return similar results, they track the same between 75% and 100% as long as green's brightness is within reason. So my apologies for the first results: I repeat it for clarity: there is NO linearity problem with the new CMS. There are minor variations, but they are within what one could expect and are far beyond what I would personally expect from a consumer product.
3) I have taken my new lamp out and put back my old lamp, so the settings below may be better for some PJ.
4) There is a substantial difference between the measures taken by my i1pro and my d2. I attach a few files for those who are willing to look at the details, but would really appreciate if a 750/rs20 user with a meter they trust could try both settings below and tell me which one looks closer to rec709 on their PJ. I have my own opinion as to which one looks more "right", but I would rather not influence anyone
I have calibrated with the i1pro in user1/custom1, and with the d2 in user2/custom2. I have set gamma to normal and color temp to the default 6500K in both to make sure I'm not introducing unknown variables to the equation.
Here are the settings (HSB):
R=-4 -21 -2
Y=31 -44 40
G=-7 -42 34
C= -14 -49 40
B=30 0 -10
M=-7 0 -6
R=-15 -16 -3
Y=7 -48 40
G=-36 -45 34
C= 13 -56 51
B=34 0 -7
M=-16 0 -4
As you can see, a pretty substantial difference!
The biggest being hue for cyan and green.
I have obviously not finetuned either of these calibrations as I need to find out first which meter is "right", if any
Please Do not pay attention to the greyscale info if present in the attached files. I've only worked on the gamut.
2nd atttempt.zip 111.1708984375k . file