Folks,
I have been meaning to throw in my two cents worth in the recent
thread on looking for Iridium flares across the lunar surface but
somehow I have been forgetting.
My suspicion is that this would be an exercise in futility even
though we could be dealing with identical magnitudes between the flare
and the crescent moon at -8 mag or so (forget about the full moon and
the -12.7 mag). What makes the photography of the Iridium flare possible
is that we are capturing a moving object during the 20-40 second
exposure. As a result, we do not have overexposure but simply a nice
image across the film.
Now, if we were to shoot for 20-40 seconds with the moon (any
phase during its cycle) right smack in the middle, I seriously doubt the
quality of the resulting image since the moon exposed for 20-40 seconds
will certainly be unrecognizable. We should be getting a very serious
blur of the stationary moon!
I remember taking some night time photos a few years back of the
Chicago downtown around the lake and included the full moon within the
field of view for esthetics. Well, my four-second exposures turned out
beatiful images of the intended skyline, buildings etc but the moon was
a nice blurry circle. Now imagine doing this for 20 to 40 seconds?!
One of the challenges involved with lunar photography is the
imaging of the one-day old moon. However, its intensity is such that it
does not require 20 to 40 seconds and, yet, one would be forced to shoot
for something in this interval so as to record the complete Iridium
flare.
As much as it would be nice to have such a photo, I am willing to
bet that the only way to accomplish such a feat is with a composite
photo (one of the Iridium flare and a second multi-exposure of the lunar
disk at a significantly different exposure).
Anthony.
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This archive was generated by hypermail 2b29 : Tue Jun 12 2001 - 15:52:49 PDT