# Tried calibrating a Sharp LE820, can someone help interpret the results? (and maybe improve it)



## Professorn (Jan 3, 2010)

So today I calibrated my TV Sharp 40LE820 (at least tried) , but still new to using a i1display pro and HCFR (+i1profiler which I didn't use this time).

Gamma I know is not perfect, but it is as close as I could get it, well everything is as close as i could get it.
But, the RGB levels are driving me insane, I don't understand why I can't even touch the nasty deviation at 50% white, to adjust both ends of the scale I used color-temperature to get it close to 100%, but the middle part there, no matter what I try I can't get it to budge apart from changing gamma high/low etc which only makes it a whole lot worse (coming to think of it, the TV might not be better...  )

Average gamma is 2.2, contrast is a lousy 1053:1 not sure how to improve it without making everything else worse?

And delta luminance seems to be "way" off (to low) at all primary and secondary colors I can't figure out why, any tip on this?

The CIE chart how, what, why, it just doesn't make any sense to me.


----------



## mechman (Feb 8, 2007)

I'm not all that familiar with HCFR anymore but overall, your charts don't look to bad to me. I don't understand what's going on in the CIE chart at all. Are you supposed to measure the primaries/secondaries at different luminance? I'd just get each as close to correct at 75% and be done with it.


----------



## Professorn (Jan 3, 2010)

mechman said:


> I'd just get each as close to correct at 75% and be done with it.


That is pretty much what I did when I tried to adjust primaries and secondaries  But the CMS LE820 is far from good in my experience and from what I've heard others say and this panels have a awful push in the green and yellow =/ And CMS is to limited to correct it.

Well well, at least the picture is a thousand times better now, than what it was with standard settings


----------



## scarolinus (Dec 28, 2014)

Professorn said:


> That is pretty much what I did when I tried to adjust primaries and secondaries  But the CMS LE820 is far from good in my experience and from what I've heard others say and this panels have a awful push in the green and yellow =/ And CMS is to limited to correct it.
> 
> Well well, at least the picture is a thousand times better now, than what it was with standard settings


Hello to All,

Just to give you an idea of my experience; I am a retired professional television/film production engineer and spent hours across dozen of monitors dealing with similar problems. 
If I may, I have a few suggestions to try:
1. Darken the room. Incident light reflected off of the display screen will influence the results as will the color of the room light, and differences in selected color temperature. Professional television monitors use CIE D65(6500° K) and computer monitors D93(9300°). Incidentally there are D65 led room lights available.
2. If the monitor has a "backlight" adjustment, be very careful to set it such that the display with a "black" input is barely visible. Backlight can cause major issues with color simply because it is seldom uniform and introduces "noise".
2. Start off with a gamma of 1.4 to 1.8. This will typically require playing the contrast and brightness adjustments off against each other and should get you into the mid range of your display even though it may not be perfect.
2. Use a stair step pattern, either five or ten steps, and check the second step from the top and bottom steps. Adjust these to be as correct using the individual RGB black and white adjustments until they measure as white or black as possible, then check the top and bottom steps. The "white" should not "bloom" and the "black" step should be just so dark as to be nearly invisible.
3. Repeat adjustments as needed for brightness, contrast, RGB black and white adjustments.

As to luminance: I seriously doubt that you will get much more than 1000:1 without comprimising something else. Also keep in mind that gamma is not a straight line from black to white but rather the slope of a line tangent to the input vs output of a display. The reason for the 1.4 to 1.8 is to match the characteristics of both film(H-D Curves) and television cameras.

Incidentally there is a 1976 CIELUV standard that may be easier to follow. Your monitor may be designed for that rather than the 1931 CIEXYZ.

Now for the expensive part. If you can find someone who has and is willing to let you borrow a Phabrix SxE pattern generator and Klein K-10 Colorimeter you're one step ahead.


----------

