look at Phils test at f4, 1/250sec....kinda blue!
my post back in September
http://www.dpreview.com/forums/read.asp?forum=1009&message=3334281
manual metering in the 707/717 for flash photography and higher
shutter speeds are just not very good. Even thou the camera sets
itself to daylight WB when the flash is engaged it does seem to
link its metering to the ambient light prior to flash. Ive seen a
tiny bit of this with my ol 707 but not as severe as what you have
here. This is what i suggest you do. Setup this same studio with
same subjects or other or with just a big dark and white cloth if
you want.
Take 1 pic with the darker cloth as you have with the subjects and
look at the exposure. Then do the same with a white cloth and look
at its exposure. Again, there may be a sight difference in the
background illumination from the flash but not as severe as your
others. try that.
Also, its best to keep your max shutter speed when using flash at
1/125 because the cam is just too freaky at higher speeds.
I think a combination of the dark clothing and high shutter speed
is the prob.
Let me know what transpires. Ill try to duplicate this prob too.
Zipper,
Thanks for your response and suggestions.
I use very high shutter speed to minimize effect of any other
ambient light and have the photo exposed to flash light only. This
simplyfies post-processing since I have to deal with only one type
of light only.
This worked very well with F707. It also worked with F717 except
these five pictures in the middle of forty pictures. I used the
same camera setting and same external settings including the
distance of the subject from the camera for all those 40 pictures.
The problem came and went away before I realized there was a
problem.
I was under the impression that, when you are using a flash and
camera knows about it since the flash setting was "forced on all
the time", camera would stop "white balance" algorithm and set
the white balance to pre-programmed fixed value.Apperently, this
may not be the case. The color of the background and the color of
the subject may be influencing the algorithm of white balance. It
seems, the camera does not use a pre-programmed, pre-determined
white balance when using a flash. I.E., it is allowing some
biasing based on the subject colors and background colors.
Next time, I will set white balance to "Day light" when I am
using a flash. I hope, this would make camera stop algorithm of
white balance and leave it alone at "Day light".
Since flash light is equivalent to "Day light", it should work.
I will let you know what I found.
Thanks for your input,
Bharat J. Sutaria
