Calibrating Monitors

[Glenn Chan]

1- Paper charts suffer from metamerism (e.g. from illumination, and the camera's spectral sensitivities; and most cameras cheat in their color matrix, which is not correct; and then there is metamerism between different observers' eyes).

You wouldn't use them to calibrate a monitor.

2-

These days, getting manufacturers to agree on a standard, even for something so universal as color reproduction, is a nightmare. No wonder the Roman Empire fell.

The standards are pretty good in specifying how levels should get converted... it's pretty much followed in the professional realms (software bugs and user errors aside).

In the consumer side of things... the main problem is that the wrong luma coefficients are *intentionally* being used... I believe this is a cost-saving measure in low-cost hardware implementations. The ITU-R BT.709 committee really should have listened to Charles Poynton and not have changed the luma co-efficients.

2b- Manufacturers of consumer TVs don't try to make their sets color accurate / conform to the standard. So that is why we don't have similar color reproduction between sets.

3- One could argue that the bellenuit approach to their test chart and Vegas' approach to levels is not good design.

[Daniel Alexander]

Hi,
Ok so i just got my JVC TM H150C after reading great reviews for it, and i was all set for calibrating it due to hundreds of 'how to's' on the net. HOWEVER, little did i know that all these sites i had been seeing where intended for NTSC monitors and often referring to using HUE as a technique where in PAL land the hue switch is not accessible nor necessary.

Well after trying to do it by playing with various functions i have to admit defeat, nearly all attempts are leading me to the same result, which is my video footage looking washed out with exaggerated banding and way way over exposed. What comforts me is i have been reading over on a few forums that other people with the same monitor after just buying are also getting a washed out over exposed image.

I know im going on abit but you can imagine how important this is to me, which leads me on to some more info that can possible help someone help me. I've been generating my pal smpte colour bars through sony vegas 8 and i notice that at the bottom far right corner where theres suppost to be 3 vertical lines of grey and black, it only displays the dark grey one on my JVC monitor. I read in the manual that this is due to my computer missing a codec which i dont understand at all. However I cant seem to find broadcast standard PAL bars on the web anywhere, not smpte ones anyway. Im getting quite worried now.

I understand also that colours will be displayed differently on my computer as opposed to my monitor but i've tried endless amounts of footage and even commercial dvds become way over exposed on my monitor.

Any help would be welcome. Thanks

[Chris Soucy]

I may be missing something, but wouldn't it be a lot easier to simply plug your camera straight into the monitor and fire up the colour bars on the camera?

This does, of course, require your camera to have colour bars available.

(What? No Canon XH A1/ G1?)

Then there's the other obvious question - doesn't the monitor come with any calibration system of it's own?

Manual?

Web site?

Support?

Seems a strange way to sell production monitors.


CS

[Daniel Alexander]

Thanks chris, getting colour bars is my secondary problem really, yeh i can get them from my camera but my main concern is the actual calibration process as this is very new to me. Especally seeing that the type of bars my camera outputs (sony ex1) are very different to the bars i am seeing.

After extensive searching on the net it seems to be quite a common theme, there are no clear guidelines on how to calibrate a PAL monitor, only rough sketchy cross conversions from how its done on an ntsc.

[Daniel Alexander]

ok so i have kind of fixed my problem. It turns out the reason i was getting an over exposed and washed out colour was due to me plugin my composite into video A instead of video B (dont know why this makes a difference but it does). I thought i should mention it as i have found so many people with the same problem i had, so i hope they find this.

[Guy Godwin]

OK folks in another thread I spoke about just buying a new V8000W LCD Ikan monitor.

Now that I have it I need to Calibrate it. I have seen the name spider tossed out there but I am looking for an inexpensive way and simple way to do this.

Also, I am wondering How can I calibrate a monitor if my camera level has not been confirmed? Do I assume the camera defaults with a good white balance are nominal for all colors?

Anyway, hopefully this can be a usefull discussion for all party's.

[Bill Ravens]

I used to think a monitor cal using a Spyder or Eye1 was necessary for good color rendition of video displays. The reality is that spectrophotometers are designed to cal screens for PRINTER colors and not NTSC colors. So, a hardware spectrophotometer is not the right way to cal your monitor.

The best way is to use an ARIB multi-format color bar, available in a number of places including the internet or directly from your camera. The correct process involves adjusting black bars called pluge according to these instructions:

http://www.videouniversity.com/tvbars2.htm

[Guy Godwin]

Bill,
Thanks for the link.
I went through it and got hung up.....
I don't have the chroma control it calls for. All I have is saturation and tint to change the colors and none get me all B&W shades.

[Chris Hurd]

Moved from Canon XL2 to SDTV / HDTV Video Monitors.

By the way we must have a couple dozen threads on this topic -- will try to find them and merge them all together. Please search first before posting new threads. Thanks,

[Guy Godwin]

Originally Posted by Chris Hurd

Moved from Canon XL2 to SDTV / HDTV Video Monitors.
By the way we must have a couple dozen threads on this topic -- will try to find them and merge them all together. Please search first before posting new threads. Thanks,

Chris, I actually did search for this item. But I will also be very honest when I did not find as quick as I wanted to I re-posted. But I will dig much deeper.

Thanks

[Chris Hurd]

Went back five years, found 24 similar threads, merged them together and "stuck" at top of forum index list. Remember when using the Search function to search the *entire* site. Hope this helps,

[David Knaggs]

This question is specific to the Mac platform.

I was looking at buying the Matrox MXO next week as I have a large project to color correct and all of the footage (35 hours of tape) was captured with the current versions of FCP and QuickTime (6.0.4 and 7.5 respectively). Normally, this would be a "no-brainer" as my calibration requirements are only for PAL or HD (Rec. 709) and I believe that the MXO will calibrate both on an ACD (this large project requires Rec. 709 calibration). So a "working" MXO would really be perfect for me (with the iMac I recently purchased).

But I've just checked the MXO forums today and they still haven't fixed the MXO to work with a current Mac system of FCP/QT (after nearly two months!) and so it can't be calibrated. Unless you downgrade your system (maybe). But that wouldn't work with my footage anyway (captured with the latest FCP/QT).

So I'm wondering what other options are out there for calibrating an ACD (or a Dell UltraSharp)?

Or have most people just been using the MXO?

I know a little about cineSpace (using an Eye-one2 probe and generating a 3-D LUT to load into Color).

But are there any other calibration options people have used successfully?

Thanks.

[David Knaggs]

Just to answer my own question, Matrox finally provided a fix last Friday (5th of September):

Matrox MXO User Forum :: View topic - Fix for MXO DVI Monitor Calibration with QuickTime 7.5

So I've now got the Matrox MXO and an Apple Cinema Display. Problem solved.

[Boyd Ostroff]

Just got an MXO myself and ran into this problem on Tuesday. As you note, there was a patch which was posted on their site, and it works.

But here's something odd. I calibrated my 23" Apple Cinema Display to my satisfaction and double checked it a few times. Looked very nice. Then while editing in FCP I had a look at the built-in color bars (on the effects tab). They seem to have a different black level than the Matrox clips. I am not in the same place as that system at the moment, but I'm pretty sure they were both set to 7.5 IRE. I used NTSC bars for standard definition in both cases.

Will have to look at this a little more carefully next week, but has anyone else noticed this?

[Michael B. McGee]

Originally Posted by Bill Ravens

I used to think a monitor cal using a Spyder or Eye1 was necessary for good color rendition of video displays. The reality is that spectrophotometers are designed to cal screens for PRINTER colors and not NTSC colors. So, a hardware spectrophotometer is not the right way to cal your monitor.

The best way is to use an ARIB multi-format color bar, available in a number of places including the internet or directly from your camera. The correct process involves adjusting black bars called pluge according to these instructions:

- Color Bars

Does anyone disagree with Bill? i'm in the process of finding "true Color" on my monitor for editing and viewing purposes on a Dell LCD monitor.

thanks,
Mike