[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Panasonic Monitors



Mail*Link(r) SMTP               RE>Panasonic Monitors

Reply to Larry Barth's posting

Larry,
I would have responded earlier but it was real busy around here.  I have a
couple of Questions and suggestions for you re < your Panasonic Monitors.

1.   Re < Noise.  Is the White  Level noise from the monitor and not the
signal feeding it?  We have been using these monitors for about 1 1/2 years
now and haven't seen this particular problem but then we mostly monitor in
Analog Composite, only using the Serial input occasionally. Hopefully that
will change very soon as we finally get Serial Switchers around here.  I'll
have to look a bit more carefully at Serial Sources to see if we have the same
problem. How's your serial jitter?  We did have a peculiar problem initially
in Composite Analog mode with thin saturated color lines at diagonal angles
that broke into a series of white dots in the decoder stage but this was
resolved with a firmware change.  Some kind of Comb Filter error but no longer
a problem.

2.   Re < CIE coordinates don't match with Color Temperature?  We use the
Phillips PM5639 CRT analyzer here (a very recent acquisition) to check color
temperature and dark to bright levels.  It can also read the CIE Coordinates
of the individual phosphors.  The CRT used by Panasonic is the same one used
by Barco, Asaca, and Ikegami with a SMPTE C phosphor.  The coordinates we read
for the RGB phosphors are below;
..........PANASONIC............SONY.........SMPTE C Published Spec
R.....x=.631, y=.341......x=.632, y=.335......x=.630, y=.340
G.....x=.305, y=.587......x=.309, y=.606......x=.310, y=.595
B.....x=.159, y=.070......x=.152, y=.065......x=.155, y=.070

Although both the Sony and Panasonic x,y CIE coordinates are a little
different they are both real close to the SMPTE Spec.  We had a lot of trouble
with our old Minolta Probe.  It wasn't the latest type and hadn't been
calibrated for a while so part of the problem is our fault for not keeping it
current.  We would get readings that didn't make sense such as a drastic
change in reading on the same monitor after recalibrating the Minolta halfway
through the monitor alignment.  The Phillips probe is much easier to use and
has plenty of open memory positions for different phosphor sets.  We normally
use the factory supplied SMPTE C memory for our readings. 

3.   The Panasonic Probe is close but not perfect. The main thing is it is
very repeatable. When we originally got our Sony monitors we found the Sony
probe didn't hack it.  2 monitors set up with the same probe wound up with
very different looking displays. We have written a User reading into the
Panasonic probe and found it gets the CIE x,y coordinates within +/-.002 when
setting up monitors throughout the facility.  We used a circle wipe pattern
surrounded by black  with 30 IRE and 80 IRE as our reference levels for
checking gray scale tracking (CIE x,y for D6500K).  Due to slight mismatches
in the gamma curves of the 3 guns/phosphors the image will be slightly
Greenish in midtones and slightly Bluish/magenta in the darkest lowlights. 
CIE Coordinates for 30 and 80 IRE are right on.  We found this to be so on the
Sony's as well.  The Panasonic Probe does not set Brightness and Contrast.  We
use the Phillips for this.  We have settled on 30 IRE = 1.14 ftL, 80 IRE = 20
ftL and 100 IRE = 35 ftL (overscan mode) for NTSC signals with 7.5% Set Up. 
For Non Set Up signals (PAL, RGB, Serial Digital, etc.) the equivalent level
to 30 IRE is 24% = 1.14 ftL (do the math for 80 IRE).  

3.   I don't understand your statement about Color Temperature and CIE Minolta
readings not corresponding.  Are you using the same device to determine each? 
Color Temperature is usually expressed as a CIE x, y coordinate. D6500K =
x=.313, y=.329.
Dave Corbitt  <dc at mte.com>
Manhattan Transfer/ voice 212-687-4000
--------------------------------------