One other thing I've noticed about the histogram is that it plots
the JPG-encoded data. That means log-X (so it's linear in
stops). Also,
the blown highlight indications aren't completely accurate. If
you shoot
RAW, there's often a stop of lattitude more than is indicated by
blinky
highlights on the histogram.
I use the in-camera histogram as a rough guide only for this very
reason, I
have the camera set for low contrast/medium saturation to broaden
it's capture
a bit however the only histogram I trust is the one in the PCR
dialogue.
Similarly, I don't really look at the in-camera histogram much when
I'm saving in RAW format. I have the highlight warning blinkies on
and have learned about how much it displays, with my camera set to
all the defaults for in-camera JPEG processing, so it is now a
reliable indicator to tell me whether I've got the exposure in the
right ballpark.
Incidentally looking back at some successful moon shots my settings
for the
following lens stack A*300/2.8 + 1.4X-L + AF Adapter 1.7X were
EI200 1/50 @
f11 and this was though light cloud cover.
http://homepage.mac.com/ramarren/photo/PAW4/07q.htm
taken with:
Canon 10D + EF300/4L IS + 1.4x Extender II
ISO 400 @ f/5.6 @ 1/500 sec
Godfrey
