[Tig] 6500 v 9300

[glenn chan]

As far as I know, the standard for monitoring in Japan is 9300K (or
D9300?).  They also use EBU phosphors/primaries instead of SMPTE C.
This would have made sense at the time since most consumer sets (all
CRT) average to EBU primaries and D9300 color temp.  Though it
arguably would not have made sense to monitor at 9300K.

Nowadays the newer display technologies are going to be closer to D65
than 9300K...

2- The standard for Rec. 709 is D65, which is NOT the same as 6500K.
D65 represents daylight illuminantion, whereas 6500K is based off the
light from a black body radiator.  D65 is slightly greener.  *You can
take advantage of ITU's 3 free downloads promotion and read Rec. ITU-R
BT. 709 for yourself.  D65 has chromaticity co-ordinates of x=0.3127,
y=0.3290

Spectrally, D65 is close to daylight (very spiky if plotted on a
graph) while 6500K follows a black body radiator (smooth curve).  You
can see graphs here:
http://www.brucelindbloom.com/index.html?CIESpectralCalcHelp.html

In practice, the subtle difference between D65 and 6500K likely
doesn't matter at all.  Firstly, many sources get it wrong (e.g. books
on color, prepress, broadcast monitors, color probes).  Secondly, it
doesn't seem like people can tell the difference.  Your eye will sort
of "auto white balance" to what you're looking at, so it'll look
white.  It's only at extreme differences (e.g. 9300K versus D65) that
you can tell a difference... e.g. reds appear de-saturated, so some
monitors compensate for this by decoding red differently/incorrectly.

The other reason why it likely doesn't matter is that you should
eyeball white points on all your monitors (and lighting) so that they
match.  See http://www.filmlight.ltd.uk/documents/FL-TL-TN-0101-StdColourSpaces.pdf

Glenn Chan
Software
Toronto, Canada