[APML] flared stars in one corner

["Bobby Middleton" <bobm@koyote.com>]

I've had a few problems with my  12.5" newt on a few pics. I've had
some random trailing across the entire field on a few shots. This occurs
more often
when I shoot far southern targets like the helix nebula. This would be
either
an out-of-tune mount or some flexure between the camera and guide tube.

I have another problem I've seen on a few shots. I've posted 2 cropped
portions
from one shot.

http://www.koyote.com/users/bobm/12problem.htm

Funny thing is I did a pair of this target and the other neg looks
exactly the same. You will see one crop (the top) from one corner is pretty
much OK
except for what I assume is the normal minor coma from an f/7 system. The
length
of this crop is about 1/4 the length of the neg. The bottom crop shows much
more severe
flaring of stars from the opposite corner of the neg; they are flared into
1/3rd of the
entire neg. The bottom crop is the same scale as the top.

I did a N2 purge on this although I am introducing from the back of the
film.
So I'm not sure this is adequate. Is it film creep or something else?
Bobby Middleton


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