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(meteorobs) Shooting the skies



      Hi John,
                    Being an astrophotographer for many years, I have learned
that the best f-stop for shooting the skies with print film is either F 4.0,
or F-5.6, using ANY film.
Most photo Labs, simply look at astro negs, and run right by them. So, it is
best to tell them to print them at two units less then their equipment tells
them to do. I have NEVER had a photo lab do any good sky printing, the skies
usually come out either a milky-black, or too dark. Thats why I have learned
to do my own! When they print too dark, they loose a lot of the fine detail,
especially the faint thread-like streaks of meteors.
   I have found that it is best to use color slide film for this recording
work. While color slide film has to be projected, ALL of the stars and trails
DO come out on the film. There is NO loss of fine detail due to paper printed
overexposure.
     There is a very nice recipe that I have for shooting black and white
slides, with NO loss of faint detail. If you or anyone ever developed film in
a small developing tank, this is the way to go! The best feature of slides is
that you can then have prints made from them easily with little, or NO loss of
faint detail at all!
   Sometimes, with wide opened lenses, you get sky fogging, this is the
results of overexposure on the film. and is not easy to correct. That is why a
lot of sky photos are gray instead of black also. If they are attempted to be
printed as a black sky due to overexposure, there is at least a three
magnitude loss of stars in the final print. 
   I agree, long exposures are required, but the rule of thumb is that the
higher the F-stop number, the longer you can expose for fine detail. Also, the
high F-stop will always give the sharper image!!!!
   I have been doing this photography for years, and have written an
astronomical guide a number of years ago,  and am revising it when time
permits me to do so... like on cloudy nights, or rainy nights!, or under full
moon conditions.

                                                                            Ha
ppy skyshooting!

                                                                        John -
Voyage! Magazine
 

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