Callibrating an LCD screen

[tricky]

We have just received new machines and new monitors. We have opted for the HP 30" flat panels due to space, power requirements and simplicity over a dual CRT monitor setup.

We are now at the point of calibration.

Now I have read a lot of posts, and with my CRT setup, I think I had it clear in my head how to use the LWF process. We were using Vlados Method 2 (M2) from the sticky post on this forum, and using the ColorCorrect plugin where we needed to guarantee colours of maps/colour swatches.

Now we have upgraded to XP64 and hence Max 9 64bit and VRay RC3 64bit. All fine and dandy!

Well it was, until I open some of my old Max scenes and note that the ColorCorrect plugin isn't available for 64bit Max 9. "Oh well, I'll use the AF Material Correct plugin instead" I thought.

However, it seems that in moving to an LCD setup, the colour/gamma/brightness issues have surfaced again. So I thought I'd better use my Monaco Optix XR (Pro!) calibrator and make a new profile etc and use Vlado's Method 3 (M3) as it appears that LCD screens work more linearly anyway. Vlados first point for M3 is to calibrate for Gamma 1.

Right then.

Launched the Monaco software and it asks me what gamma setting I want to calibrate to, but it only give me the option for 1.8 or 2.2.

So, where do I go from here? Do I need a profile at Gamma 1 or should I just calibrate it to Gamma 2.2 as with my old CRTs?

Hope you understand me????

[Paul Oblomov]

Well, you have to calibrate to 2.2 (sRGB).
But, it seems to me - itsa waste of time...

[timmatron]

Why a waste of time? We calibrate our lcd displays to 2.2/6500k and it works fine. Without calibrating we'd be all over the place.

[tricky]

C'mon - anyone. What should I be doing? Vlado? Should I calibrate to 2.2 even though it is an LCD screen?

[timmatron]

Yes! The reason there is no option for a gamma of 1 is because nobody works like that.

[kimgar]

øhm, got sRGB, but no gamma option on mine...but paul, at the risk of sounding real dumb now, do you mean that sRGB = 2.2 gamma?

[tricky]

Yes! The reason there is no option for a gamma of 1 is because nobody works like that.

Surely this is a bad idea though? LCD works far more linearly than crt, so calibrating an lcd to 2.2 would surely push things way out of kilter?

Vlado! HELP!!!!

[dlparisi]

øhm, got sRGB, but no gamma option on mine...but paul, at the risk of sounding real dumb now, do you mean that sRGB = 2.2 gamma?

Accoirding to wikiepdia (http://en.wikipedia.org/wiki/SRGB), it's pretty darn close to 2.2.

BTW: I calibrate my 24" dell LCD using the GretagMacbeth/Pantone Eye-One Display 2 to 2.2 gamma and haven't had any complaints from clients and matches pretty well to professional prints (close enough to avoid any surprises at least). Colors and tonal ranges match pretty well from this monitor to my laptop also calibrated the same way (although it ends up at gamma 2.4 since that seems to be as close as it can get it).

[dlparisi]

øhm, got sRGB, but no gamma option on mine...but paul, at the risk of sounding real dumb now, do you mean that sRGB = 2.2 gamma?

Accoirding to wikiepdia (http://en.wikipedia.org/wiki/SRGB), it's pretty darn close to 2.2.

BTW: I calibrate my 24" dell LCD using the GretagMacbeth/Pantone Eye-One Display 2 to 2.2 gamma and haven't had any complaints from clients and matches pretty well to professional prints (close enough to avoid any surprises at least). Colors and tonal ranges match pretty well from this monitor to my laptop also calibrated the same way (although it ends up at gamma 2.4 since that seems to be as close as it can get it).

[kimgar]

ah, thanks for clearing that up dlparisi - a bit too late to dive into that wiki, but 'pretty darn close' works for me

[sea2stars]

1) I use a LCD monitor. Ive been reading in this thread that LCDs have very different gammasettings than CRTs. Should I still calibrate my LCD to gamma 2.2? or should I use some other value?

From what I understand, you need to calibrate your LCD monitor to act like a CRT one with 2.2 gamma and then proceed as with a CRT monitor applying all the gamma stuff. My Samsung SyncMaster 213T has a program called Natural Color that calibrates the LCD to act like a CRT monitor.

Best regards,
Vlado

[dlparisi]

One other thing I should point out with my calibration was that the Eye-One setup allows to adjust the monitor for luminance or something like that by adjsuting the brightness of the montor. During this setup I adjusted the brightness of the monitor down to "7" (out of 100). Again, these settings seem to match up pretty well to prints.

[Rhys]

just got the hp 24 inch hp lp2465 and just started using lwf and am at the same stage of software calibrating the monitor. Now i've noticed under color settings in the hardware of the monitor i can it to 6500k which i believe is what everyone says to set to. Otherwise there sRGB there the instructions say.

sRGB Support

The monitor is designed to support sRGB for color management,
which adapts to the color standards used in the image technology
industry.
To take advantage of the sRGB support, you will need to change
your monitor’s color temperature to sRGB and install the sRGB
color profile (ICM) file.

✎The sRGB color temperature preset will improve the color
accuracy of sRGB images on the computer monitor, but some
color variation may still occur.

Now should I use that or should I set my monitor to 6500k and then use a gamma chart and set it to 2.2 and adjust from there. ?

[Dschaga]

Some historical facts:

Multimedia settings: 6500k /gamma 2.2 (pre intel apple: 1.8!)
Print monitorsettings: 5000k /gamma 1.8 (^^^^reason why everyone thinks apples are better for graphics)

now:
sRGB ... the industry wanted a color space which can be handle even from cheap devices -> don't use it if you want the highest possible quality, because this will limit the colors from nearly every TFT on the market!


.. and here other somehow odd facts about tft calibration:

first : I have a 24" Dell (uses a samsung panel like the HP24" and nearly all other 24") and i can say, that gamma isn't the problem. The Dell have a very limited colorrange which is slightly wider then sRGB.

The typical behave of tft's:
You will get the best color rendering with brightness 100% (DELL:500cd/m2 = insane!) ..but when you want to work longer then for 30 minutes you should calibrate the brightness to ~160-180cd/m2

Here is the problem:
Example: a tft with 1000:1 contrast and 500cd/m2 and 8bit/color = 256shades /color!
->> Now reduce the Brightness from 100% to 50% (250cd/m2) and you will get only 128shades/color and contrast is less then 500:1 .. this is enough for something like a gray gradient, but the extreme red's and green's are gone!

The only solution to this problem is a TFT with 10bit/color (1024 shades/color) like some nec's /eizo's - some more bucks to invest anyway!

..so that's why calibration is good but solves not a basic problem of tft's

btw .. do not calibrate your TFT for any gamma(1.8-2.2), instead use L* (Lab) if possible ..this will give you the most natural colors!

The drawback of L* .. ... you have to rethink the LWF , because when you adjust your gamma in MAX(because there seems to be no other ways to adjust the max screen) you will get a screen gamma from 2.4 and more and then the question is what you want to do with the input gamma and outputgamma to stay in your workflow.