A Monitor OSD Calibration Revelation

[xpatUSA]

The trouble with knowing everything is that you don't.

Every since I got my first TV I thought that brightness set the whiteness of the screen and that contrast set the darkness or (later) the slope of the video to luminance curve.

Then recently I found that I had totally screwed up my NEC monitor settings. After a factory reset, I fiddled around and got it a bit mo' better but not perfect. So off to Google-land I went.

Turns out that my life-time concept of the two controls was totally backasswards. As everybody here except me knows:

Brightness sets the black level.
Contrast sets the white level.
They interact, requiring iterative adjustment.

Glurk.

Unfortunately, the NEC has a separate black level control. Would you believe that, out of an hour's-worth of intense googling, only one page (Toms Hardware) actually mentions that control, what it does and how to adjust it ?!!

My NEC User manual says - "Black Level: Sets black level". Double glurk.

So now I'm back to knowing everything . . . until the next time

[Manfred M]

The advantages of the profiling and calibration tools is that they hide all that "stuff" from you and they take care of it in the background. With my rather ancient i1 Pro, I have to manually set the brightness and contrast to "as low as it will go" for the profiling / calibration to work properly.

If you think about it, this makes sense. Your black level is effectively what your screen looks like with brightness set all the way down (black being the absence of colour), so the liquid crystals in your display will be twisted so that they block all of the back-lighting that they can.

[dje]

Ted I saw an article by Charles Poynton talking about Brightness and Contrast adjustments in which he mentions the sort of thing you refer to above. I suspect his comments were based on CRT displays but I'm not sure. I suspect that LCD monitors may be more complex and also vary from one make and model to another. eg My Benq doesn't have a Black Level setting, nor does it have an adjustment for backlight level. My research caused more confusion and frustration than enlightenment and took me to the point where I was happy to not know everything !

Dave

[xpatUSA]

Ted I saw an article by Charles Poynton talking about Brightness and Contrast adjustments in which he mentions the sort of thing you refer to above. I suspect his comments were based on CRT displays but I'm not sure. I suspect that LCD monitors may be more complex and also vary from one make and model to another. eg My Benq doesn't have a Black Level setting, nor does it have an adjustment for backlight level. My research caused more confusion and frustration than enlightenment and took me to the point where I was happy to not know everything !

Dave

Hi Dave,

Yes I read one of Poynton's articles too and the one I read said it was for CRT monitors with LCD amendments to follow. According to Tom's Hardware the NEC monitors are the only ones with a separate black level adjustment. Apparently, unlike your Benq, the brightness control does adjust the backlight power and therefore the black level as a side effect sorta kinda like. I envisage it (or "envision it" as they say over here) as raising and lowering a constant slope line on a graph of video in versus luminance out. and the actual black level control as setting a limit below which the so-called 'brightness' adjustment can not go - that would put a knee into the constant slope line and, of course, cause a loss of shadow detail. Summat like that, anyway.

You might this of interest:

http://www.lagom.nl/lcd-test/

I used it today and gained a bit of improvement over previous efforts.