[Tig] RE: monitor calibration

TAKIS at prodigy.net TAKIS
Thu Jun 2 04:31:40 BST 2005


I was surprised at the lack of responses to Martin's 
monitor cal post. 
Does this mean that it's such a boring subject, 
everybody has it down to a science now with no points 
of contention? 
My guess is most out there have and possibly continue 
to struggle with these Sony BVM monitors. 
As we all know, Martin is putting the time in the 
educate us. 
Let's give him some real world working information. Do 
you want an alternative to these beasts someday, help 
him get there 
Here is my very specific telecine environment 
procedure. 
By the way, once set up correctly, these monitors do 
not drift much, the $40,000 BVM-D32E1WU is rock solid 
in my experience. 
SMPTE C Phosphors here in US 
Sony Evergreen series monitors BVM - 20F1U the SD 
standard found in most telecine bays 
Sony Multiformat series monitors BVM - D24 / D32 the 
HD standard found in most HD / SD telecine bays 
8 color bar 100% or SMPTE for SD. 8 color bar 100% or 
HDW bars for HD. 
Split field color bars with PLUGE Note: some devices 
clip at 0 IRE, removing the PLUGE level below black. 
100% White box or window over black 
20% Gray box or window over black 
Philips PM 5639 color analyzer Note: Factory 
programmed for D6500 xy chromaticity coordinates x 
= .313 y = .329 
Sony BKM-14L Auto setup Probe, used for white 
uniformity on D24s, digital uniformity adjustment on 
D32s only, do not use for color calibration for 
critical monitoring. 
BKM-12Y memory card used to save calibration values. 
proper color temp referenced / backlit / neutral 
gray / wall or lighted surround / for vision reference 
The above is the ideal starting point. 
I have worked out this procedure after many years of 
calibration experience with the Sony BVM series 
monitors. 
The procedure is the same for HD or SD 
That means 23.98psf for the most HD, and some 1080i 
59.94 and the usual 525 for SD. A serial digital path 
and optional input cards for the above monitors is 
asumed. 
Monitor test signals are available from many 
companies, the one I have used are the Evertz 7750TG2-
HD Note: Monitor test signals not available in 
23.98psf from this Evertz. 
Ensemble Avenue 7405 HD TSG has the monitor test 
signals also available in 23.98psf. 
I do not use the internal test signals for 
calibration, only for convergence. 
After configuring input, (use channel set only, do not 
attempt to copy from one channel to another, create a 
new channel for every type of standard or frame rate, 
SD, HD, NTSC, PAL,DI, etc. Using channel set only, 
means that you must manually configure and calibrate 
each individual channel. 
Turn on brightness hold. This is important. 
White field purity and convergence, sizing, for 
underscan / overscan, stable operating temp. (monitor 
stays on 24 / 7) are assumed to been achieved before 
color temp calibration is attempted. 
For the larger HD monitor, the optional Sony probe is 
needed to run Digital Uniformity alignment manually 
across the CRT. 
SD channels set for 4X3 underscan. 
HD channels set for 16x9 underscan. 
Apply bars to input, 
Perform the automatic adjustment using AUTO menu A12 
in control preset. 
Apply 100 IRE window over black. 
Carefully position suction cup of Philips 5639 probe 
over white part of test signal, Correct setup, 
operation and calibration of philips meter is assumed. 
Use contrast / brightness control presets to set for 
30 FTL on meter. 
Apply 20 IRE gray window over black. 
There is no published target value for black level. I 
use .78 FTL 
Perform color temp adj, by using RGB gains for white 
point (100 IRE, RBG bias for black, (20 IRE gray) 
Set for 6500 K using magnify function on Philips 
meter. 
Go back and forth between white and black until target 
values are achieved. 
30 FTL at 100 IRE white window at 6500 K 
.78 FTL at 20 IRE gray window at 6500 K 
Apply split bars with PLUGE 
Set brightness for PLUGE, lower 2 chips to blend / 
disapear into other raster black, while clearly seeing 
the brightest chip of the 3 level PLUGE. 
There is some subjectiveness to setting the "black 
level" of the monitor by this method. Most agree 
pretty much, with the occasional colorist requesting 
the PLUGE to be set a little higher. 
There is always the option (and danger) of taking the 
monitor out of preset, (brighjtness only) for a 
session should the colorist desire. That creates the 
possiblity that the next operator might not notice. 
This should be the only reason why an operator would 
have to intervene with a calibrated monitor. Nothing 
else can be set by eye.
 
If the brightness is changed to achieve black level 
according to PLUGE, you must go back and forth with 
the 100 IRE window to maintain 30 FTL 
The . 78 value is discarded in favor of the value set 
by EYE using the PLUGE as described above. 
The final check should be in blue only to confirm 
phase and saturation are correct 
I'm sure everybody has their variations and little 
tricks. 
I have found that deviating from using 20 IRE or 100 
IRE is not necessary. 
If the CRT is in good condition the black point will 
track down to the darkest blacks. 
If it does not and you are sure everything was done 
correctly then it's most likely an indication that the 
CRT should be replaced. 
Disclaimer: I was given an "Evergreen" mouse pad by 
Sony when they first came out. 
I have received no compensation by any of the above 
mentioned companies. 
The folks at Ensemble were nice enough to put these 
monitor test signals in their generator at my request. 
(Sorry, they could only fit in 2). 
I must thank Jason Selek, former Sony monitor 
specialist for his help over the last few years. 

Dennis Politakis 
Engineer 
Matchframe Video 
Burbank Ca. 91505







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