RE: [APML] May Lunar eclipse camera?

["Scott Hammonds" <capella@creatorsview.com>]

Thanks for the responses. I'll give it a practice run over the next
month or so and let you know how it goes. I knew I could do this but was
looking for that easy out.

Scott Hammonds

 

-----Original Message-----
From: astro-photo-bounces@seds.org [mailto:astro-photo-bounces@seds.org]
On Behalf Of astropix@att.net
Sent: Thursday, March 27, 2003 3:06 PM
To: Discussion of Film Astrophotography
Subject: Re: [APML] May Lunar eclipse camera?

 Scott writes:
> My
> problem is my current cameras don't offer the ability to shoot the
same
> frame multiple times...

 Hey Scott... I recall you're using Canon equipment. My FTb QL manual
instructs 
that you push the canister release button, turn the rewind crank 7/8 of
a turn, 
then turn the film advance/shutter reset lever... without holding the
release 
button, of course. This is inaccurate as far as this type of Eclpise 
photography goes. You can get some decent double-exposures this way...
see:

     http://home.att.net/~astropix/Down_Town_Double_X.html

... but not the precision desired for the shot you seek. 'Hat Trick' it!
Here's 
how: First, get to the darkest location that's practical for you.
Ambient light 
will quickly fog the film with this technique. Next, carefully place the
camera 
in the position it will be in for the duration of the exposures.
Probably best 
to do some dress rehearsals with the selected equipment in the nites
preceding 
the actual event. 

     Begin the first exposure by covering the aperture with a black card
and 
locking the shutter release cable in the bulb position. (you will leave
the 
shutter locked on bulb the entire time) Remove the card to effect the
exposure. 
Cover the aperture at the end of the exposure with the card once again, 
then :::install the lens cap::: to wait for the next exposure time.
Remove the 
lens cap several seconds before time for each exposure to allow
vibrations to 
dampen... remember to have the card in front of the lens before removing
the 
cap!

     I have two different black cards I made from black foam-core. One
will 
cover the front of my C-8. I used a large wooden paint paddle (for 5
gallon 
buckets) super-glued to the foam square as a handle. The smaller, camera
lens 
sized one has a foam-core handle... I even added a piece of black twine
as 
a 'strap' to the small one so it can hang from my wrist while I fiddle
with 
other things! I painted a light coat of ultra-flat black to the business
end of 
things. These have worked very well for me... I don't bother with mirror
lock-
up on my deep sky shots anymore... I lock the cable with black card in
front of 
the scope... count 3 for things to dampen... and begin my exposure by
removing 
the card from in front of the aperture. I end my exposures in reverse...
block 
the aperture, then release the cable lock.

     Covington has very good recomendations on exposure times and field
of 
view. I'd refer you there for lens selection. He's a mathematician...
I'm just 
a mechanic...   :O)

 Hope This Helps...

 Geoff

--
http://home.att.net/~astropix/
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