You don't need to set the exposures at different plus factors as
a thru the lens meter will compensate for the differences. Why go thru
all the trouble of three exposures when in Photoshop you can easily
change color balance, selective color, curves contrast etc on any
image, even a moving image. Popular Photography is making precise
measurements with colors under test conditions to show the differences
between cameras. However the real world changes with the Kevin light
levels sometimes in very short time periods. If you want the absolute
best color or the color you remember do it in Photoshop and have a
Merry Christmas.
Roy
In a message dated 12/18/2009 10:30:52 A.M. Eastern Standard
Time,
tmi@xxxxxxxxxxxxx writes:
take some testing to get balanced exposures. As a starting
test I would
try 3 stops for each of a 25-58-47B tricolor set or 29 red = +4.3
stops,
61 green = +3.3 stops and 47B blue = +3.0 stops. for daylight. What
this
would give was a way to test digital camera color. For example the
digital camera reviews typically say that a Sony A850 does not have as
nice a color as say a Nikon full frame camera. I have wondered how
subjective this judgment is. Could it be that contrast or other factors
are confusing the color evaluation? By shooting tricolor through a
digital camera on three separate RGB shots using filters like 25-58-47B
or 29-61-47B you would have a way to evaluate the color yourself.
First,
you could combine the separation images in Photoshop and compare them
to
the normal digital camera shot visually. Second, you could use the
difference combine mode to subtract one image from the other and have
an
image that was the difference between the normal digital sensor image
and the separation RGB image of the sensor. Since the registration
would
be inherent, the images would be aligned. If the differences were
significant this could offer a way to get nicer color for landscapes or
still life images where movement of the subject was not an issue. Since
the digital sensor spectrum plots I have seen - not often offered in
detailed versions by manufacturers - seem to show significant color
overlap I bet it might be possible to get purer, dye transfer-like
original images this way. Has anyone tried this?
