[tig] Monitoring question

Dave Corbitt dcorbitt
Mon Nov 15 13:39:59 GMT 2004


At 08:00 PM 11/12/2004, lunarfilms wrote:

>> > I have a question you might be able to help me with.  I have been in a
>> > bit of an argument over our edit set ups here, whereby they were not
>> > configured with a TV monitor (NTSC or otherwise) and I have shown that
>> > you cannot see the true picture from a film transfer on the computer
>> > monitor.  The contrast on the computer is so intense that the depth of
>> > the film that was shot is lost. While I understand that the inherent
>> > nature of video can prohibit the true film picture vs it being
>> > projected, there are those here that contend that what I am seeing on
>> > the TV monitor is not really there (which is ridiculous) and that it is
>> > adjusted without a true black level.  They also like to spout that
>> > video technology is such that all TV monitors are going to become like
>> > computer monitors and I should get them to light according to that
>> > final picture and output; therefore, the crappy picture on the computer
>> > is the real picture.  This is frustrating because I know that you would
>> > typically use a good monitor to edit film going back to film but I need
>> > a good technological explanation for the vid geeks.
>> >
>> > Bill
>> >
>> >
>> >
>> > William Donaruma
>> > Dept of Film, Television & Theatre
>> > Notre Dame, IN  46556-4600
>
>Robert Houllahan


Here's your argument. High Quality broadcast monitors are precision display 
instruments capable of a very wide contrast range, are built using selected 
primary colors of Red, Green, and Blue set to very precise standards years 
ago by industry watchdog and standard setting commissions such as the CIE, 
SMPTE, ITU, and EBU, and are designed for a specific gamma characteristic. 
Color temperature and grey scale tracking are or should be carefully and 
routinely calibrated using precision colorimetric analyzing equipment such 
as the PM-5639. Computer monitors, on the other hand, are not standardized, 
do not use selected primaries for RGB, are difficult to calibrate for color 
temperature tracking, and generally have non-standard gamma characteristics 
changing the tonal scale of the display to be different than that on a good 
video monitor. All the above is old news to people in our industry and it 
always surprises me when these old urban myths keep coming back as if these 
issues were not settled years ago. A good post facility engineer will know 
how to calibrate monitors and will do this routinely, checking black levels 
against a Pluge signal, checking overall levels and grey scale tracking as 
well as image size and amount of overscan. Using BVM or equivalent quality 
monitors insures the coordinates of the primaries are according to industry 
spec. So, if you are viewing your edits on computer monitors, all bets are 
off. If you are viewing them on broadcast grade monitors that have been 
properly calibrated, you will seeing the images correctly in all their full 
contrast range and color subtleties, or in all their horrible inadequacies 
due to their poor handling or source material. We have known this for years 
in telecine and get excellent results using good monitors that can 
reproduce most of the subtleties of film faithfully. To make a statement 
that "all TV monitors will become like computer monitors so get used it" is 
ill informed and just plain wrong. Anyone who follows the home theater 
movement knows that the broadcast standard is the ideal and that consumer 
gear has gotten much closer to that ideal in recent years due to the strong 
advocacy roles of consultants who have taken to task the home video display 
manufacturers' poor performance in years past and brought them up to speed. 
These advocates have produced DVDs full of test signals and started a minor 
industry of trained calibrators who hire themselves out for the sole 
purpose of calibrating home theaters. Consumers are willing to pay anywhere 
from $300 -1000 a pop to have their systems calibrated. The results are 
terrific and allow the good work of so many of our colleagues to actually 
be seen properly in the home.

Dave Corbitt
Post Logic NY






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