Originally Posted by randal_r
These are not easy questions to answer in a quick phrase. First one must assume that you are calibrating a 10 point or a 20 points grayscale if you are going to be adjusting the display at these levels. If you are doing a 2 point or a 1 point calibration then the question does not apply. The 2 point method is to adjust the 30% / 80% levels while other displays suggest 30% / 100%. With this method 20% percent and below you really don't have much control. I have taken the liberty to look up the manual for the LCD display that you have. This is a 2 point white balance system.
I feel that every question deserves a fair answer and I am limited by my experience and knowledge; so here we go.
"if you only had i1Pro and had to calibrate all of grayscale - how would you do it if under 20% it wasn't good?
As aforementioned, this is a 10 or 20 point grayscale calibration. One would adjust these levels the best they could but also one would look for discolouration out of the norm; such as the black having a Green tint to it. One would look at the DeltaE and to see where it is on the scale and adjust accordingly. According to some experts, the human eye can distinguish discrepancies better at 30% & above then at 0% - 20%.
The signal noise issues at dark levels causes the spectrometers to become less accurate hence the reason for the long read time and since a colorimeter is not effected in the same way one can see as to why a dual system is desirable. As for downloading a correction file this is like taking another person's prescription; it wasn't meant for you.
I am more than willing to try and answer your questions but there are many out there who would question your understanding of the foundation video calibration. Like all of us, we are in a constant state of learning. I don' know if you have taken any formal training like IFS or THX classes and I know to some they are expensive. May I suggest you look into Michael Chen's Video Tutorials, they are economical and informative. As for now I will strive to answer any question I can.
Er.... doing only 30% and 80/100% is not the way to go. I have an LCD with a 2pt controls and if I were only trying to get 30% right and 80/100% right - a whole lot of grayscale would be inaccurate. You need to do at least a 10pt read and get all 10pts as accurate as possible. Most movie content uses 5-35% so if you have to prioritize - that would be the range to prioritize. If you followed my posts and calibration results you would know that I do know what I am doing. What I do not know - I ask. I do not know much about spectrometers other than they are considered more accurate, but now it seems its no longer the case! First I asked about them - I got a whole lot of replies with links that show that Pros would go for a spectrometer for being more accurate OVER i1D3 colorimeter and now different people say "i1D3 changed the game - use that instead". It is a matter of opinion then.
I keep on asking people "if you had only ONE device" and half the answers are "you need more than one device if you want to get it right!" - I know and I also stated that I know, but that was not the question! So a whole bunch of pros would go for i1Pro instead of i1D3 and would use their eyes to calibrate 20%-10%? That would only help if the discoloration is obvious, but if you want to have a truly accurate calibration then i1Pro alone in some cases would be worse than i1D3 and vice versa. So, you couldn't really say which one to use unless you knew just how accurate i1D3 was on a specific screen.
OK, another question - HOW inaccurate
is i1Pro 5-20%? Any i1D3 probe can be off by dE 2-9
. If i1Pro is less accurate at 5-20% than at 20-100%, but still manages to be more accurate than i1D3 at 5-20%
then it does make more sense to have just i1Pro as the only device. In MY experience - i1D3 is very accurate on CCFL screens and seems to be accurate on plasma screen, but is NOT accurate on LED screens.
I do know that each display needs its own calibration and profiling, but in case with many monitors - variances between the same exact model are not as high as with TVs. I downloaded profiles which I verified with my colorimeter and they were very close to being accurate. The downloaded correction file provided me a far better result and its obvious because the result is neutral and not purple!Edited by MonarchX - 1/29/14 at 11:40am