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Hello everyone.
I’am trying to make a 3d lut with mad vr for a videoprojector and i have a few questions.
Is it really necessary to do a Interactive Display Adjustement before launching the calibration and profiling process ? If I don’t do that, is white point will be calibrated at D65 Or Not when i play a video with my 3d lut and madvr ? what are the cons and pros to not doing this ?
After the calibration, i’ve launched a black clipping video and a white clipping video test with madvr. The video test for black clipping seems to be Okay but not the white. Before the calibration, the white clipping was pretty good 230 to 234 but now the clipping go to 253. I have tryed to change input encoding (Clip WTW) but with no succes. What can i do to Get a correct white clipping.
Last question, in the measurement report, what is the Measured vs. assumed target whitepoint *00 ?. All my result are okay exept that.
Thanks for your answers.
Mickael.
Hi,
Is it really necessary to do a Interactive Display Adjustement before launching the calibration and profiling process ?
No, you can also let the 3D LUT do all the work, in which case you disable interactive adjustment on the “Calibration” tab and make sure white point is set to “As measured”. Then you only need to make sure prior to profiling that none of the channels are clipping (which you should anyway).
what are the cons and pros to not doing this ?
One of the pros is that a whitepoint adjustment via the display controls will affect all displayed content, not just through the 3D LUT. If you have no need for that, then adjusting the display white point prior to profiling isn’t strictly necessary.
Before the calibration, the white clipping was pretty good 230 to 234 but now the clipping go to 253. I have tryed to change input encoding (Clip WTW) but with no succes. What can i do to Get a correct white clipping.
If I recall correctly this is a madVR quirk. Try setting madVR to use “windowed overlay” in its rendering options, which I think has been quoted on Doom9 forum as a possible workaround.
Last question, in the measurement report, what is the Measured vs. assumed target whitepoint *00 ?. All my result are okay exept that.
The assumed whitepoint is derived by going from the correlated color temperature of the measured whitepoint to the nearest “daylight” chromaticity (with the same CCT). If the assumed and measured whitepoint aren’t close together, this probably means you didn’t measure through the 3D LUT (or didn’t adjust the whitepoint, in which case it may simply not be close to the daylight locus).
Hi Florian,
Thanks for your answers
How can I check if the channels are clipping ?
I don’ need to adjust the white point for all displayed content, I will just use the 3d lut to watch movies with madvr. So, I don’t need to use IDC
Thanks for the “trick” with madvr. Is there another way to fix this in case of ?
I don’ remember if I do the measures with the 3Dlut. I think so because the delta E are correct for grey and colors but there are a 7000 k normally they have to be at 6500k. So something tell me that I do the check whitout the file. You can find the report in attached file. Maybe you can tell me if I do the check with the 3dlut file ?
Another question. Is it possible to fix the luminance of the white point for the 3d lut ?
Thanks a lot for your answers and your help.
Mickael.
How can I check if the channels are clipping ?
The clipping videos you used should suffice, in addition to B & W there should also be one including color steps for RGB and CMY (be sure to temporarily disable the 3D LUT in your player while checking channel clipping, e.g. in MPC-HC, press CTRL+SHIFT+3).
I don’ remember if I do the measures with the 3Dlut.
The report was made without 3D LUT active. Do the following:
- On the “Display & Instrument” tab, select “madVR” as display.
- On the “Verification” tab, enable simulation profile and set it to Rec. 709. Choose the same tone curve parameters as used on the 3D LUT tab when you created the 3D LUT. Also enable “Use simulation profile as target” and “Enable 3D LUT”.
- Run the report as you normally would.
Another question. Is it possible to fix the luminance of the white point for the 3d lut ?
Not sure what you mean by this.
Thanks for your quick answer.
For the last question, I want to know if is it possible to set the white point to a specific value. For exemple i’ve got my video projector with a white point at 80 cd/m2 and I want it at 55. Is it possible to set the value to that for my 3dlut file for playing a movie with a lumiance that I have specified or I need to set the luminace in another way ?
Thanks.
For the last question, I want to know if is it possible to set the white point to a specific value. For exemple i’ve got my video projector with a white point at 80 cd/m2 and I want it at 55. Is it possible to set the value to that for my 3dlut file for playing a movie with a lumiance that I have specified or I need to set the luminace in another way ?
You can set a target luminance on the “Calibration” tab when tone curve is not set to “As Measured”, but for a projector it is usually advisable to reduce the lamp output to the desired level to prolong its life.
Ok, when I am selecting a tone curve for a gamma 2.2, I can change the white level to a custom value. I thought that the calibration Tab was for 1dlut, ls the custom white level will be applyed to my 3d lut file if I change it or i will have to apply a icc with “DisplayCAL-apply-profiles” to get the selected value ?
Thanks.
ls the custom white level will be applyed to my 3d lut file if I change it
Yes, but I would really recommend adjusting the projector lamp itself instead.
I am already in “ECO MODE” for the lamp to reduce amount of lumens. I don’ know If I can do something else to adjust lumens output, maybe changing the Contrast of the VP.
Thanks for all of your answers. It will be more easy for me now to play with displaycal and adjust my settings 😉
Ps: I will try the Madvr trick asap to tell you if is it working.
Hello Florian
tried to tick the box in madvr but it doesn’t Work. Still have the clipping with the white vidéo test.
Mickael
tried to tick the box in madvr but it doesn’t Work. Still have the clipping with the white vidéo test.
It’s not really a problem though because normal video material does not extend into WTW range.
Ok, i will use it like that but i continue to search if i can have something correct. What does WTW means? I know it’s for white clipping, but i don’t know the signification.
Thanks
