FW: [Tig] D-Cinema Suite contd.

Dave Corbitt david.corbitt
Sat Mar 8 23:01:45 GMT 2003

At 4:23 PM -0500 3/8/03, John Frey wrote:
>Kevin Ayres supports the TIG.
>Stan Chayka wrote:
>>  The point to consider is that when the white bar is exposed, the light level
>>  behind the pluge area is actually higher making the point of extinction that
>  > much harder to set.
>>  I would like to think that if the pluge is used to set the extinction point,
>>  it be done without the contamination of the color bars, and, then see if the
>>  blacks match better with projection systems.
>Interestingly, I have a couple of PAL generators which have a pluge 
>set amidst a largely black field.  ..............
>What should we do?  Put a pluge in a grey field?

Stan, John, et al,

I have heard from reliable sources that when the Pluge was added to 
the color bar signal there was a lot of disagreement among the SMPTE 
RP committee members of the usefulness of a Pluge added to a bright 
signal such as Color Bars due to the exact same reasons being brought 
up in this thread. However, the rational forces did not win out in 
this case and Pluge added to color bars is now basically not very 
useful. The fact that it is in the corner also doesn't help things as 
most monitors will have a significant light drop off in the corners 
relative to the center. For that reason, home theater calibrators use 
pluge signals that are centered on the screen on a  black field and 
go from top to bottom of the frame. You can see this and many other 
well thought out calibration signals on the two most popular DVD's 
used for monitor calibration. It might make good sense for post 
production and broadcast engineers to borrow some lessons from their 
less well paid home theater calibration cousins. I can tell you the 
names of these DVDs if you contact me privately.

Disclaimer: I am currently unemployed (hopefully only temporarily) so 
I don't take any money from any monitor calibrators or anyone else at 
this time.
Dave Corbitt
Madison, NJ 07940
email  david.corbitt at verizon.net

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