Calibrating a Monitor

[Eric Sipe]

I did a search for calibrated calibration and calibrating and didnt find anything on this.

Hopefully this is the right area.

I have a samsung 22" LCD, and I manually adjusted it myself with no program just what i "thought" was the right colors. it looks good to me, but I know it HAS to be off. Is there any software/trial or place or program i can run so i can attempt to adjust my monitor so it shows the right colors/contrasts/brightnesses etc etc?

[Paul Cronin]

google "eye-one" It seems to work great.

[Bill Ravens]

if you're meaning a cal for video work, I suggest you're concerned with setting up your monitor to be NTSC standards compliant. Any spectrophotometer, like the Eye-One, won't really set you up to be NTSC compatible. What you need is a color bar test pattern with pluge bars. Do a search on wikipedia, it'll start you in the right direction.

[Harold Schreiber]

Hi Eric,

I picked this up some where.

You do need a proper color blue film strip to use color bars for set up.

Harold

[Glenn Chan]

SMPTE color bars aren't really appropriate for computer monitors.

The easy answer is to get a broadcast monitor (CRT) if you are doing SD work.

[Eric Sipe]

I will be doing HDV work. Video editing. Also i plan on Photo editing manipulation.

Would any of the aforementioned tests work with any of these? for the bar test seach wikipedia for it, then get a "true" blue strip and put it up to the monitor and match the colors that way?

[Graham Risdon]

Sorry if this is hijacking the thread but... I've seen loads on calibrating NTSC monitors, but virtually nothing for PAL monitors. HAs anyone seen/got any good info on calibrating PAL monitors for SD or HD?

[Rich Dykmans]

For photo editing get a Spyder2, under a $100 and does a good job. Doing that allows your high end editors like PS to display color properly on your LCD.

But as was pointed out a computer LCD does not offer the same gamma response curve as a true video monitor and suffers from YUV to RGB conversion as well. Output color bars in the format you're working in (HDV I believe you said) via your NLE or off tape and at least get the contrast/brightness adjusted via the pluge bars. If your LCD offers manual color/hue adjustments then the blue film over the color bars could work. If not you'll need some sort of SW controls that will allow you to adjust your LCD's color while still displaying/updating the bars in the backgound.

[Glenn Chan]

Color bars do two things:
A- They calibrate the interface between the monitor and whatever is feeding it. For broadcast monitors, that would be something like a composite connection.

In video signals, it is possible for the test pattern generate to generate signal that is "blacker than black" (or below black level). In the PLUGE bars, the left bar is supposed to be blacker than black, the middle bar black, and the rightmost bar above black. You calibrate the interface by setting black level until the left bar disappears but you can still see the right bar.

With computer monitors, you either have:
--DVI connection. No calibration needed.
--VGA connection. You can't send the blacker than black signal from bars over a VGA connection.

B- They also "correct" for glare on the screen. When you calibrate the PLUGE bars, you make a subjective assessment as to when the left bar disappears while you can still see the right pluge bar. This is a subjective calibration, not an objective one. It also depends on the amount of light hitting the monitor.

2- To calibrate a computer monitor (the interface, i.e. VGA):
There's different ways of doing this. (CRTs) One way is to display a full screen of black. Use the v. position control on your monitor to move the entire picture down.
Adjust "brightness" (really, this means black level) until your picture is indistinguishable from the part of the monitor that isn't being scanned.

3- The problem with computer monitors is that they don't do certain things the same way as TVs. For SD work, they don't overscan (i.e. they don't crop off the sides), they don't show interlace flicker, they don't have non-square pixels, they don't have the same color response as a CRT, etc.

HD monitoring has slightly different issues... i.e. price, de-interlacing, LCD vs CRT (each has its weaknesses)

[Boyd Ostroff]

If you haven't already seen it, this article discusses some of the basic adjustments: http://www.videouniversity.com/tvbars2.htm

[Glenn Chan]

In response to an email...

Should I go to Home Depot and get reference samples of blue/red/green?
No. For monitoring video, the standard chromaticities (particular shade of color) of blue, red, and green are either
SMPTE C (for SD, for NTSC countries except Japan)
EBU (for SD, for PAL countries and Japan)
Rec. 709 (for HD); this is also the standard for computer monitors

These are all different sets of colors.

In practice, a broadcast monitor with phosphors that correspond to any of these standards can be used for the others. (This is what happens in practice.) We tend not to notice color inaccuracy, esp. when colors are varying in the real world anyways (the real world is 'color inaccurate').

If you get a monitor, just get one where the colors aren't too far off from the standards. The easiest way to see is to have a bunch of monitors side-by-side, and see which match the high-grade CRTs with SMPTE C phosphors. There may be an easier way of doing things.

2- If you have a LCD with DVI, you can't do all that much to calibrate it better.

The best you can do is to make sure nothing is monkeying with the image...
The monitor's controls are neutral
No video overlay settings in the graphics card
No LUTs in the graphics card
Your NLE displays video accurately (most can't be trusted).

If you want better quality monitoring, then buy a high-grade reference monitor. With the consumer stuff, there isn't much point in doing more than the above. The monitor will have inherent flaws that can't be calibrated away (or aren't worth the effort): black level, phosphors or R/G/B color, response time / ghosting.

[Eric Sipe]

MAybe then "calibration" is not the right word choice here.

I can adjust the Gamma, the Red Green Blue settings, etc etc. To get quite a different look. I remember editing photos on my old CRT and where i thought it was BLACK, when printed out it ended up being GREY and lots of "artifacts" in that area that i COULD NOT SEE AT ALL.

I do not want to "Edit" photos or videos where it "looks good" on my screen but when i produce it, it looks like "sh%$^$" and clearly not what i want from it. Is there anyway i can eliminate this from happening or at least REDUCE this from happening? i guess thats my better question.

[Liam Hall]

Originally Posted by Eric Sipe

I did a search for calibrated calibration and calibrating and didnt find anything on this.

Obviously, you didn't look here then;

http://www.dvinfo.net/conf/showthread.php?t=89302

Liam.