Originally Posted by rajapruk
I am trying to calibrate my projector (an old Samsung A800b from 2009) but I got some problems.
I am using a colorimeter (x-rite i1 display pro) and measuring software (HCFR).
This projector has an kind of semi-automatic calibration function. You should measure red, green, blue, and white (d65) from internal test patterns in the projector, and then enter those values into a calibration table in the service-menu. Then the projector calibrates itself into almost perfection. That is how it is supposed to work.
When I measure the internal test patterns on my screen, I get this values for Red as an example (xyY):
Red x: 0.6540
Red y: 0.3375
Red Y: (cd/m2) 14.772
Red Y: (ftL) 4.2928
Then when I look into the calibration table in the Samsung-projector, there is already values like this:
I do not get how to map these values. I do not get what units the projector wants.
For x and y it seems to match if I multiply the value from HCFR with 1000.
For luminance (L), I do not get it. How to map the value Y in HCFR to L in the Samsung?
I realised later that I should have turned off the existing calibration in the service-menu before measuring. So, I will have to remeasure. But, I still wonder what exact unit of measures should be entered in the Samsung Color Temperature table, especially for Luminance (L).
At first this is from the service manual, how to measure:
- Selects whether to apply the white balance adjusted using the CCA.
- ON: Applies the CCA.
- OFF: The CCA is not applied.
- Defines the standards to be used in the user menu.
- SMPTE-C: The color coordinate standard for analog signals.
- EBU: The color coordinate standard for D-TV signals used in Europe.
- HD: The color coordinate standard for D-TV signals used in the USA.
The Brightness and Color Coordinates for Primary Colors
- Measure and input the brightness and color coordinate values for Red, Green, Blue, and White of the test pattern in the
- The measurement should be performed in a dark room with no outside light.
.- Use a measurement instrument such as a CL-200 (illuminometer) or CS-1000 (luminance meter), etc.
- Measure the center of the screen with a measurement distance of about 1.5 to 2m and a screen size of 40”.
- Enter the measured values and then measure the color coordinates of 6500K White in the user menu. The measured
color coordinates are good if they are within x:0.313±0.003 and y:0.329±0.003.
- If the value is not within the range, perform the measurement again
This is my Samsung SP-A900B, default settings.
Red x 651
Green x 292
Blue x 148
White x 328
How to plugin your measured data
For the x_y data you use the three digits after 0, - in your case for red 654 and 338.
For the L = luminance you take the measured data, in your case data Red L 4.2928*150=644 (Thats around your original 638) then you multiply your other luminance numbers with the same amount - that's it.
The multiply of 150 isn't very important just it is the same for all 4 luminance measurements.
This info I got from a professional Samsung/Joe Kane trained calibrator who calibrated mine.