Re: Perseids, After Hours

[P3D KENNETH LUKER <KLUKER@xxxxxxxxxxxxxxxxxxxxxxx>]

Well, I was right.  We missed all the meteors when the shutters were 
open.  Let me pass on to anyone interested the things I think I'll do 
differently next time.

The exposure was not intense enough.  The photoprocessor returned the 
negatives as a strip, although I'd specified that I wanted a contact 
print sheet.  S/he had thought the negative strip was blank, and that 
a contact sheet would be a waste of my money.  In fact, the contact 
sheet probably would have been helpful even if it had come out mostly 
black, because as I look closely at the negs, I can see the stars on 
them.  But if I had used a faster film than the 400 I used, there 
would have been more obvious images.  

The exposure was too long.  The one-minute exposures had slight star 
trails; the 2.5 minute exposure had star trails 2.5 times as long 
(Duhh!)  Any meteors shown would have been long streaks with tailed-
stars as the background.  I would like to have had point-like stars 
as the background.  Had I used an equatorial mount, I could have had 
what I wanted.  Next time I'll use much faster film and expose for 
maybe half a minute.  

The time between exposures was too long.  In order to be sure of
getting meteors, I should have just shot more film, probably
exposing for half a minute with high-speed film, then winding the
film in the next fifteen seconds and exposing for another half a
minute, etc.  I would go through a lot of film, but that's
relatively inexpensive compared with waiting a year for another
chance.  I could quit when I ran out of film or money.  Or I could 
use that money to buy an equatorial platform and keep the shutter 
open for many, many minutes.

Any clouds in the sky tend to spoil the effect.  Since over a two 
mile baseline the clouds tend to be entirely dis-similar, I couldn't 
even get good hypers of the clouds.  Anyway, the clouds moved during 
the long exposure and were exceedingly blurry.  Best to remove all 
clouds from the sky before attempting astronomical stereographs.  
:)

Since I got no meteors in the shots, I did not get a validation of 
the choice of baseline.  I still think the two miles was about right. 
When I find evidence one way or the other, I'll report it.

Now, when does the big Leonid storm come?  November?  Let 'em come!
Ken Luker
_______________________________________________________________
Kenneth Luker
Marriott Library Systems and Technical Services
KLUKER@xxxxxxxxxxxxxxxx


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