Monthly Archives: March 2015

Post production: CRT vs the Panel Display

Video image finishing is the last step before the distribution of a motion picture project.  It stands to reason that the quality of the video monitoring equipment being used by the editor or colorist is essential for producing the best looking end product.

At our editing suites, we continue to rely on our inventory of legendary Sony BVM-D20 and BVM-D24 color critical, evaluation grade monitors for this most vital work in our editing suites and director control positions.  Sure, we’ve added various flat panel monitors to our edit systems, and they are absolutely necessary (especially with Ultra-HD).  However, there are many things that panels just don’t do very well so our CRTs will remain as part of our production chain for years to come.  Here’s why.

There is no better way to see field order defects
As panel monitors began replacing CRTs a few years ago, we began seeing (on network television no less)  judder artifacts that we would never let leave our facility.  It is partly due to field reversals.  Likely, it propagates through the transmission chain because the editors just can’t see it anymore with their new monitors.  We can’t see it either very well – on our own panel displays.  When we edit, we WANT to see such problems and it is easy on the CRT.  An essential capability of video finishing is being lost as CRTs disappear.

Panels mask field problems, either by design or by the inability to react fast enough to show them.  So who cares about field reversal if today’s consumer sets are hiding the problem anyway?  Put another way, if you can’t see a problem, is it a problem?  The answer is not quite so simple. The process of distributing content may take a technical path through compression and playback equipment that doesn’t always play nice with hidden artifacts.  Thus, a video with some ugly reverse judder that is invisible to the editor or colorist can end up being seen by all viewers at distribution.

Color grading is easier
A limiting aspect of typical panels is that you really only get a good view of the picture if your head is perpendicular to the display.  You can see it on your own laptop. This characteristic was so bothersome in the early days that Apple even designed the famous flat panel imac “iLamp” with a 3-dimensional articulating arm so that you could gracefully mitigate this most annoying problem.  Granted, panels have improved but they are certainly not consistent and the need to get right in front of the monitor is still there.  So, two people cannot physically see the same thing at the same time – a real struggle in a collaborative editing session.

Our CRTs can be viewed at any angle, and the colors/luminance don’t shift at all.  There is no urge to get right in front of the monitor.  In this way, color grading is far more effortless.  The CRT shows the colors reliably.  With the panels though, there is always some lingering doubt. The CRT is the only mechanism that ever consistently achieved the venerable REC 709 color specification.

Every resolution it displays is native, not scaled
Panels are manufactured with rows and columns of pixels.  As such, they can accurately reproduce one resolution.  Feeding them any other resolution requires various tricks to scale the image in order to approximate a correct view of the picture.  The CRT instead alters its scan dimensions without having to conform to any other fixed screen resolution.  In the suite, we look for edges and gradual curved shapes in video content that may exhibit “stepping”.  At times, we may see these subtle details on the panels and ask ourselves “is that on the video, or is the monitor causing that”.  On the CRT, there is no doubt.

Happy grading!


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