Black Luminance in Calibration

[Ambrotype]

Hi Damien ,

I have a LCD monitor (LG-Phillips Slimax MF151S) . After many attempt to calibrate monitor (with x-rite calibrator and your method) I can't access to right Black Luminance .
When I reduce amount of brightness by button on screen (30) , Black luminance is 0.311 and luminance is 64 . In this situation shadows in my images match to print but screen is a bit dim !!
And when I set brightness to higher values (90) , Luminance is about 100 but Black Luminance is 0.492 !!
in both calibration results the Contrast Ratio is the same (About 200).
How can I get Luminance at 100 and black luminance about 0.300 ?!
before x-rite I used Adobe Gamma and I could set the highlights, mid-tones and shadows match to prints !!!

I,m waiting for your reply,
Thank you in advance.

[Damien Symonds]

4 hours ago, Ambrotype said:

I have a LCD monitor (LG-Phillips Slimax MF151S) . After many attempt to calibrate monitor (with x-rite calibrator and your method)

No, there must be some mistake.  You're not following my instructions.  My instructions don't talk about black luminance.

Anyway, it's irrelevant.  You're demanding precision that your screen just isn't capable of.  Just live with the best possible result for now, and put "new screen" at the very top of your next purchase list.

[Ambrotype]

Thank you so much !
I know ! you talked just about contrast ratio (native).
What is the best contrast ratio for photo editing ?! Do we have a standard value for this item ?!
When the luminance is 100 then how much must be the black luminance ?! 

[Damien Symonds]

I've read that 400 is considered a good contrast ratio - roughly 0.25 black to 100 white.  However, I've never thoroughly explored this myself.

And you need to own a REALLY expensive screen (such as an Eizo) to be able to properly control black luminance.  With your screen?  Forget it.

[Ambrotype]

Thanks again.