September 13, 2010

Is Your White Really White?

“The foundational and primary goal of display calibration is image fidelity (faithfulness to the original program)... The objective of any communication medium is to convey an original message as accurately and completely as possible. Any alteration of the message becomes a distortion of the original intent…”
- from “Display Calibration: Root Fundamentals”, an article by G. Alan Brown; President, CinemaQuest Inc.
The quote above refers to video, but the idea is similarly appealing to audiophiles. Isn’t it our holy grail to be able to playback a recording with total fidelity to the source? However, the difference between audio and video is that there are standards to follow in the video world, while I am personally not aware of anything similar in our audio world (I stand to be corrected on this point).

Thus, it is possible to get a projector or a plasma/LCD tv to display close to how the producer, the director, the artists intended the picture to be. So, for an audiophile like me who is getting into home theatre, how could I miss out on such an opportunity to do things right?

Unfortunately, things aren’t that simple. We can’t go out and buy a projector or tv, plug it in and expect the picture quality to be right according to the standards. To attract your attention in the ultra-bright environment of an electrical shop, the manufacturers have boosted the picture’s contrast to the max. In my experience, in the longer term, such a picture looks artificial and plasticky, the image edges are unnaturally etched, and looking at it for long induces viewing fatigue, not unlike the listening fatigue from listening to a hifi system that is too bright and harsh.

Take the popular demo disc at the moment, James Cameron’s Avatar. In the shops, the picture looks real cartoon-ish and leaves one in no doubt that it is all CGI. Whatever analogue feel you get watching it in the cinema is gone.

Does you Avatar look like the one in the cinema?
So, how to do it right? The answer is to get the projector/tv calibrated. You can get videos/books/equipment that teach you how to do it, or you can get the help of a professional, such as one of those certified technicians/consultants from the Imaging Science Foundation (ISF), an organization in the US “dedicated to improving the quality of electronic imaging”.

Back to the Avatar video. If you were at the recent KLIAV show, you would see it played in almost all the rooms that showed video. The AV Designs room played Avatar too, but it did not play the fighting scenes, instead it played a full blown forest scene which showcased an incredible amount of details and richness of colour. It was one of the best Home Theatre rooms for me, as their room has been for me in the past years too.

As I have alluded to in my last 2 posts on my setting up a home theatre at my new place, I started to discuss the possibility of it with James Tan of AV Designs. AV Designs is one of the few Malaysian installers certified with ISF (you can get the global list of ISF certified outfits on its website, apparently all projectors and display sets that AV Designs sell are properly calibrated by them. The quality of the picture after calibration, seen in an environment with appropriate lighting, was most definitely unlike what you see in the electrical shops. The picture from a calibrated set is easy on the eye and natural, the richness and details are all there. It is a more analogue and film-like look. On good material, it simply looks incredible. Most will think that the calibrated picture is a little too dim initially, well, I think we have all been conditioned by picture quality that screams at us a little, it takes a little acclimatization to accept a more accurate and mellower looking display.

What does video calibration involve? From the few articles that James sent me, I understand it involves adjusting the contrast and brightness, colour and tint, and the sharpness levels. And lastly, the most well known part of the procedure – adjusting the grayscale level. The different shades of white that we see are determined by the colour temperature , it ranges from 2,800 Kelvin (orangeish/warm white) to 10,000K (bluish-white). The NTSC decided that the correct shade of white for our video system is 6,500K, which apparently is close to midday sunlight on a clear day. Since a video has much white and black information, any deviation from that standard will skew the picture to that direction. On the other hand, the studio monitors, where the shows are produced, are all calibrated to 6,500K for white. So we’ll be able to view the picture as it is intended only if our displays are calibrated to the same. Once calibrated, our projector/tv will show white at 6,500K or thereabout at all light intensity level from 20 IRE to 100 IRE.

So there you go, for video, it is possible to calibrate our display to match the industry standard. When this is done and done correctly, you’ll get to see a picture quality that is faithful to the source. I shall continue to report on what I learn and see as I go down the road from here.

To enquire about ISF video display calibration, contact AV Designs' James Tan 016-3280237


Drubb said...

Actually I don't care much for home theatre. However, I am intrigued by your journey and I enjoy the occasional cookies which you throw our way. Quite educational for me, I must say, and just what I would need, to understand the ABCs of home viewing. Kalman Rubinson is always Greek to me!
It's great to know how to 'properly' calibrate one's monitor. But conditions in a 'standard' lab/room may not be similar to one's viewing room. Just as a particular loudspeaker would sound different in a different room, so would a particular brightness setting look different in a different viewing room; unless of course if it's totally dark.
I suppose one could start with the recommended white balance setting and then readjust +/- according to one's preferences. It's just like speaker placement. Start at the recommended position and move bitwise until they click.
Above a certain age, no two eyes are the same; even for the same person. The standard settings would be real unfair to a person with cataracts. Even our color perception would vary with age.
Anyway, please keep updating us on your project. I really do find it interesting.

Ng said...

Different from Drubb, I care much about AV as much as Hi-fi. Currently with the introduction of bluray in mainstream AV, For example, as much a as one enjoy Queen music on a high end hi fi two channel stereo , a Queen concert with pristine HD picture and sound offer an alternative yet similar enjoyment one get from Hifi without scarifying audio quality. Even on my reference Dave Matthew & Tim Reynolds concert at Radio City ( Bluray) which is not much of showmanship , watching and listening to their performance is as good as listening on a Hifi playback. Movies wow!! great of course. I am an advocate that both have a place in our personal entertainment lifestyle in enjoying "hi fidelity"

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