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Monitor calibration

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Pasi Koivisto
Monitor calibration
on Jul 21, 2010 at 6:09:00 pm

Hey all,

I am looking into calibrating my PVM20L4, it's drited and it's time to adjust the RGB Gain/Bias. Now, my problem seems to be that I would ideally output the test patterns from Final Cut since that would allow the complete "chain" to be adjusted for. But I can't find any pre-made test patterns for Final Cut and creating them is difficult.

How do you do it?


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Michael Sacci
Re: Monitor calibration
on Jul 21, 2010 at 8:43:57 pm

There are SMPTE Bars built into FCP.

Found via google
http://www.synthetic-ap.com/products/tpm/index.html

well maybe not, not compatible with intel macs


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Pasi Koivisto
Re: Monitor calibration
on Jul 21, 2010 at 9:36:03 pm

Sorry, I should have been more specific. These test patterns are not for setting brightness/contrast/saturation but for setting gain/bias for RGB.

So, the patterns I need to create are 10-18% big windows on black with R, G, B, C, M, Y at 75% saturation with 2.22 gamma and at 75% luminance. If I understood the very elaborate excel sheet I have.

/Pasi
--
Editor, Colorist.
Mac Pro, 8x3 Ghz, 8 Gb ram, ATI Radeon HD 4870, KONA 3, Sony PVM20L4, Tangent Devices Wave.


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Doug Beal
Re: Monitor calibration
on Jul 21, 2010 at 10:03:17 pm

Just a thought but Kona3 Control>ist drop down to test pattern> load file

perhaps you could create the required colors in photoshop, monitor your scopes off the Kona until you'd dialed in what you need, and save those patterns.

guessing you don't have a probe, and an autosetup kit installed in that monitor?

camera rental house close by with probes? Sony broadcast guy anywhere near?
that's a pretty old monitor, may be time to retire it pick up an FSI

Doug Beal
Editor / Engineer
Rock Creative Images
Nashville TN


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Pasi Koivisto
Re: Monitor calibration
on Jul 21, 2010 at 10:14:27 pm

There is a probe for the monitor it's just that the guy who's going to do the calibration (isf certified) tells me that those are not good enough since they don't correct for possible errors in the video chain and don't account for the environment where the monitor is. Not sure if I really need the color patterns since my monitor can't adjust colors, only grayscales for rgb.

/Pasi
--
Editor, Colorist.
Mac Pro, 8x3 Ghz, 8 Gb ram, ATI Radeon HD 4870, KONA 3, Sony PVM20L4, Tangent Devices Wave.


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Bob Zelin
Re: Monitor calibration
on Jul 22, 2010 at 12:29:04 am

Pasi,
unless you are a professional color grader (color corrector), it is virtually impossible to adjust the bias and gain levels by eye. You are adjusting black and white balances, and without a calibration probe from Minolta, Sony, or others, you will just make your monitor look worse. You use SMPTE color bars (available in FCP) to adjust the normal brightness, contrast, phase (hue) and chroma. The bias and gain controls are used for black and white balance.

The PVM-20L4 (and the whole PVM line) was notorious for having black balance problems (the blacks have a green tint in them), and unless you have a probe, you will never adjust these out by just tweeking the bias by eye.

Bob zelin




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Pasi Koivisto
Re: Monitor calibration
on Jul 22, 2010 at 9:47:09 am

Bob,
I do have a probe but it's not good enough since it's drifted a lot since I bought it but the certified calibrator who's going to do the calibration has one. And I am pretty sure he re-calibrates his probe annually.

/Pasi
--
Editor, Colorist.
Mac Pro, 8x3 Ghz, 8 Gb ram, ATI Radeon HD 4870, KONA 3, Sony PVM20L4, Tangent Devices Wave.


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Joseph Owens
Re: Monitor calibration
on Aug 2, 2010 at 7:53:24 pm

[Doug Beal] "perhaps you could create the required colors in photoshop"

No. Never do this. For interformat conversion reasons this is completely unacceptable.

jPo

You mean "Old Ben"? Ben Kenobi?


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