AV
December 3, 2012

ISF-certified calibration for serious videophiles.

By WL Low

 

For most of us when shopping for an AV display, be it Plasma, LCD, LED screens or a  projector system in a typical electrical store environment, we instinctively go for the brightest set with highest contrast setting due to its razor sharp picture quality and dynamic contrast that deliver visual punch. I wish to clarify that if choosing a display device in such a crude manner, we’d end up with a knock out (literally!), as the brightly contrasting screen, with razor sharp picture would prove fatiguing for long-term viewing, such as watching an entire movie.

 

I’d highly recommend for those who own big screens(55 inches or bigger) for AV pleasuredom to engage the services of an ISF-certified technician to calibrate the display to ISF standards to achieve colour tone balance, gamma (input/output linearity), tint/hue, and grey scale contrast (from the blackest black to the whitest white) for accurate picture quality, just like audiophiles  aim to reproduce music as accurately as possible with a flat frequency in room response measurement. Granted, some audiophiles will also argue that flat frequency response in itself is no panacea to great sound quality. However in the context of video, that argument is dead in the water, as the calibrated results are there for all to see clearly, even to the most un-discerning folks, such as my wife and kids!

Before(top) and after(bottom) of  RGB colour tone balance calibration. Note the flat colour response output from all three colour generators, after calibration.

 

I recently had my Samsung PN64D700 plasma screen re-calibrated by an ISF-certified technician.
He brought along with him, tools of his trade, essential for getting the job done right (don’t let anyone tell you otherwise!). The tools include a tripod-mounted photospectrometer (like the unit pictured below), linked to a laptop loaded with the necessary software (typically Calman, as pictured below in a printout of a job; NOT mine, to be specific) to interpret the results of the scan. The job took more than 3 hours as the technician did the job in the following steps.

 

1) RGB colour axis locking to ensure proper on-screen registration between the three colour generators.

2) RGB colour tone balance to ensure that all three colours output evenly across the spectrum.

3) Colour tint/hue adjustment to ensure accurate flesh tones.

4) Grey scale contrast, to ensure the display is reproducing the blacks and whites in a step by step linearity scaling.

There are some fine tuning to further refine the setting such as setting the brightness levels of the screen back-lighting to suit the room ambient light conditions.

A photospectrometer linked to a laptop loaded with calibration software are essential tools that an ISF-certified calibration technician should have to get the job done correctly.
The end result is stunning, with an even colour tone balance between RGB.
I am experiencing natural and accurate colour reproduction. Flesh tones look realistic with faces looking neither too blue or red. Landscape scenes with lots of green are recreated with a wealth of details never before seen which I never thought was there in  the original Blu-ray source. Picture depth of field is reproduced with layers and layers of  details that increase the illusion of depth, even without the use of 3D (which happens to look fake and very etched). There is so much more details in dark scenes, which makes movies like Batman, The Dark Knight, that much more entertaining. Sitting through an entire movie has never been more pleasurable. Like I said earlier, even the undiscerning noticed the improvements immediately.
A pre/post calibration report is usual;y supplied to prove the technical corrections done on one”s display set.

 

I must admit lacking the technical depth to write more about this subject other than relate a short user experience, but here”s a site link that will provide more details if one is interested to learn more about the technicalities of display calibration.

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