How to calibrate LCD monitor (LG L194WT) ??

H

HandyMan

Looks fascinating. How do I use it to correctly calibrate my monitor. I
suspect I'm over-redded and under-blued.

Civilian_Target

Download the gamma test graphic for the workspace of your choice. PCs tend to
default to 2.20 and Macs to 1.70. Before starting make sure your monitor has
been turned on for 30 minutes or so, so that all components are warmed up and
operating at working levels.

Load up the graphic in any graphic viewer and view it at 100%. It won't work if
it isn't displayed at a 100% ratio. Meaning don't zoom in or out on the graphic.

Make sure you save or write down your beginning brightness, contrast, and gamma
settings so that you can always go back to them. You can get hopelessly lost in
trying to adjust them and be unable to get back to where you started unless you
have some reset features.

Start out by adjusting brightness and contrast so that you can't see any
difference between the black and dark-gray squares on the lower-right strip, and
that you can barely see a difference between them on the top-right strip. While
doing this keep an eye on how bright your whites are, try to adjust for white at
the same time to a level that is tolerable for you. You will have to go back and
check this again after you adjust your gamma settings.

Use your gamma adjustments (sometimes in combination with contrast adjustments)
to make sure that you see an even gray ramp from pure black to pure white on the
center and left sets of vertical bars. There should be no color hue changes on
the RGB/CYM bar (center section), and all grays should match horizontally across
the board. If you see strong hue shifts you may have to adjust the gamma of each
channel separately. It's a rare monitor/video-card that will get them perfectly
gray all across so don't get upset if they're a little off.

The double-bar on the far left will match in gray levels horizontally when your
brightness, contrast and gamma is correct. You shouldn't see a strong division
between left and right side of it, or at least no glaring differences. The same
as with the RGB/CYM bars, there should be no strong division between the 3 bars.

While doing this you may have to back away from your monitor a few feet or try
to blur your eyes a bit while viewing the graphic to make the fine lines of
colors blend into solid grays. I get by with squinting my eyes to get the fine
color lines to average together for the grays. Otherwise it's difficult to make
an adjustment, back away, come back to the computer to tweak settings again,
back away, etc.

Go back and check your brightness and contrast again because changing the gamma
levels will also change your blacks. Repeat until you get it right.

If your setup is like most I've adjusted it will end up being a combination of
monitor adjustments and video-card adjustments (if your card has them). This can
get quite convoluted and frustrating when approaching it from both devices but
often it's the only way to get it as accurate as possible. Don't discount your
white-balance settings on your monitor too. Most manufacturer's default
color-temperature (color-balance) settings royally suck, and they might be
keeping you from attaining pure blacks grays and whites out of that graphic. If
you can manage to get the black, grays, and white right on a monitor (from that
graphic) then all your displayed colors will be 100% accurate.

It's a good idea to find a nice setting then wait a day before tweaking them
again. Your eyes and mind have the ability to do their own white-balancing act.
Stare at any color of light long enough and it'll look white or gray to you. You
may come back a day later and notice you have a strong color hue on your monitor
because of this. Tweak the settings a bit again if you do. When I get a new
monitor or video card I will load up that graphic a few times for a week or so
until I have reached a happy medium between all ambient lighting situations and
my own eyes trying to fool me.
 
S

support

Civilian_Target said:
Looks fascinating. How do I use it to correctly calibrate my monitor. I
suspect I'm over-redded and under-blued.

Civilian_Target

Civilian,

There's a fool proof and easy way to calibrate a monitor. I've been using it on CRT's first and now on LCD's.The only catch is you have to buy a calibrator, like one of
http://search.ebay.com/spyder2express_W0QQ_trksidZm37QQfromZR40QQpqryZspider2express
This calibrator sends signals to the monitor and measures what color the monitor emits. Based on the difference between expected and actual colors, the calibrator creates monitor's profile and saves it in the computer. Every time when the computer starts, it loads the profile.
No matter how badly you have already screwed up the settings, the calibrator fixes everything with the monitor profile. On aging CRT I had to use it quite often. On an LCD I set the colors once only.
Hope it helps.

Support
http://www.cozyworld.ca <http://www.cozyworld.ca/>
 
B

Beladi Nasralla

Unfortunately RTFM doesn't always work.

I have always prided myself on calibrating most any monitor that has come my
way. I don't think twice about opening up the back of a CRT and tweaking the
individual guns and HV section's gain to make sure I get a proper ramp on all
channels for smooth grays across the board. I mostly do photo editing so I've
avoided LCD monitors all these years. However I recently bought a lower quality
LCD Acer AL1706 monitor. An emergency purchase because my last good monitor just
died and I didn't have a replacement hi-power tranny it needed. Between the
nVidia control panel, finding an ICM profile for it (or making one), and its own
built in adjustments this was a real head-scratchier.

After about 3 days of approaching the adjustments from several directions I
finally settled on some that I can happily live with. By keeping a nice 2.20
gamma test graphic open while making the adjustments.

http://www.aim-dtp.net/aim/download/monitor_gamma/220.png(type in the gamma of
your choice, "xxx.png", from 100 to 300 in increments of 10)

Finding the proper settings ended up being a combination of installing a custom
profile that I found somewhere on Acer's site, nVidia's own desktop controls,
having to tweak nVidia's blue contrast and gamma separately, along with some
minor custom white-balance settings on the monitor itself. It wasn't easy but it
was doable. None of this complex combo of tweaks being contained in any one User
Manual. Quite frankly, for the low cost ($175) and my time spent I'm getting a
nicer display on this bargain-level LCD than I have on most CRTs that I've used.
Some of the purest grays I've ever seen and a nice even ramp from pure black to
white. Quite impressive. I won't think twice about using this for photo editing
needs. I think what I found most amazing is that when using some advanced
monitor testing software I didn't find even one hot, warm, or dead R, G, or B
pixel across the whole LCD display. How do dey do dat? Applause to their LCD
component mfg. QC team.

It's a shame that the makers of these devices don't make things easier for the
end user. They'd be able to sell so much more of them if everyone could get top
performance from them right out of the box. Out of the box on its default
settings this monitor was a disaster. The colors so over-saturated and off, so
bright and high contrast, that I thought I was having some kind of flashback.
Most of that due to nVidia's fault.

Gee, Handyman, thanks for your detailed reply. I observed funny thing:
I adjust contrast and brightness by using the gray gradient pattern,
and then switch to another grey gradient (mentioned in your links)...
and I see that my monitor is out of calibration... I do not know why
is that.
 
P

Paul

Beladi said:
Gee, Handyman, thanks for your detailed reply. I observed funny thing:
I adjust contrast and brightness by using the gray gradient pattern,
and then switch to another grey gradient (mentioned in your links)...
and I see that my monitor is out of calibration... I do not know why
is that.

The first product specification I could find is here:

http://uk.insight.com/apps/productp...product_id=LGEMM194WT&nbs_search=C=113&S=1071

LG L194WT "Image Contrast Ratio 2000:1 (dynamic)"

What that means, is calibration will be useless. The monitor will be changing
levels, based on the image content. Since the response of the monitor is
dynamic, no fixed calibration will exist. Either find a way to disable the "dynamic"
feature, or shop for a monitor with a more realistic contrast ratio. A
product with a contrast ratio consistent with the physical limits of
an LCD panel, is more likely to calibrate and remain constant for
Photoshop usage. Say 500:1 or so. Units offering 2000:1 or 3000:1
will be fiddling with the image while you work.

This is an example of a monitor more suitable for Photoshop.

LACIE 321 Black 21.3" 20ms DVI LCD Monitor 250 cd/m2 500:1 - Retail
http://www.newegg.com/Product/Product.aspx?Item=N82E16824196010

Notice that the response is 500:1, which would suggest there is no
"dynamic" behavior to image rendering.

There are a couple reviews of that unit, to read here:

http://www.amazon.com/LaCie-Monitor-21-3-Panel-108368/dp/customer-reviews/B0007WZODO

Paul
 

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