[stepmback]

I have a displayi LT2 that I bought recently and have been using with HCFR. According to the documentation from HCFR I should point the light meter at the screen and adjust (angle, height) until I get the maximum ftl. This is done, I assume to remove shadow that the light meter and tripod cast as much as possible.


I have a 1.3 studiotech screen and when I adjust it appears that I am still getting the shadow. If I want to set contrast or brightness can't I just point the meter at the project and adjust that way? Then setup meter at screen for other measurements?


Also, how do you set contrast, with a light meter or with a test patern. I say this because according to HCFR, I should increase contrast until it peaks ftl. That for is MAX contrast, which can not be right.

 

[Michael TLV]

Greetings


You don't set contrast and brightness with a meter on a digital projector. You do it with test patterns and with your eyes.


regards

 

[stepmback]



Quote:
Originally Posted by Michael TLV /forum/post/14259001


Greetings


You don't set contrast and brightness with a meter on a digital projector. You do it with test patterns and with your eyes.


regards

That helps greatly. Previously when I was calibrating I had a consistant gamma of 1.9 across 20-90 ire. That is with my gamma correction off. Should I calibrate with gamma correction off, then turn it on and take another reading. Or should I be calibrating with Gamma on?

 

[Michael TLV]

Greetings


Trial and error ... but generally do it with all corrections turned off. Nothing kills you if you do it both ways to see what happens though. A learning experience.


Regards

 

[Doug Blackburn]



Quote:
Originally Posted by stepmback /forum/post/14258963


I have a displayi LT2 that I bought recently and have been using with HCFR. According to the documentation from HCFR I should point the light meter at the screen and adjust (angle, height) until I get the maximum ftl. This is done, I assume to remove shadow that the light meter and tripod cast as much as possible.


I have a 1.3 studiotech screen and when I adjust it appears that I am still getting the shadow. If I want to set contrast or brightness can't I just point the meter at the project and adjust that way? Then setup meter at screen for other measurements?


Also, how do you set contrast, with a light meter or with a test patern. I say this because according to HCFR, I should increase contrast until it peaks ftl. That for is MAX contrast, which can not be right.

Sounds like you may have the meter too high. Another way to look at the meter is to consider it a calibrated substitute for your eyes. If your meter is on the same axis as your eyes, it will measure from the screen, the same thing your eyes see. You can sit in your main viewing position and put a pattern with a central "bulls-eye" up on the screen. Measure the height of your eyes from the floor, and measure the height of the bulls-eye target from the floor. If the meter is on a tripod half-way between your viewing position and the screen, split the difference between your eye-height and the bulls-eye height. For example... if your eyes are 36" and the bulls-eye is 48", with the tripod at half-distance, you'd want it about 42" high to be on the same axis with your eyes.


If the meter is not on the same angle as your eyes, the screen may return a different amount of light to the meter vs. to your eyes depending on how directional the screen is.


You won't use the meter to set either Brightness or Contrast controls - though you can measure your final setting for 100% white just so you know what it is. Depending on your projector, screen, and room lighting, you may or may not be able to measure the black level (0% white) with your meter. Knowing your black level is interesting but ultimately not useful for any calibration purpose other than sifting through various settings which may raise or lower the black level. Obviously, you don't want to use settings that raise the black level - the blacker the better. As long as the control in question doesn't make 0% darker while something else is messed up badly.