Here is what I did to make my camera
with electric shutters usable and at the same time more versatile then
my manual camera. First of all I cut a piece of wooden doweling approximately
the same dia. and length as the 2 internal camera batteries, then I soldered
the thinnest wires I could find to the ends of a couple of steel rivets
,inserted them into the predrilled holes as in the drawing making sure
they would match up with contacts inside the camera. In the case of my
battery door it just about closes so I use a little metal clip to hold
the door shut, you could use an elastic or tape if you like. Next in a
Radio Shack project box I put 2 penlight batteries in a holder with an
off on switch, ( I would guess at this point that most cameras I am referring
to, use 2 batteries, 3 volts DC ) using RCA jacks to make connections and
a phono cord in between, you have now got an excellent Astro camera. In
my particular case I installed this assembly in my hand held dual axis
corrector box. At this point I would like to point out why you might want
to do this and where the versatility comes in.
1. First and .MOST IMPORTANT you make
use of another camera, one you may have given up with and
put away.
2. You can open or close the shutter
without leaving your guiding eyepiece.( less chance of bumping or
just causing vibrations in your mount
).
3. A 555 timer can be wired into the
box so auto exposures can be attained.
4. I think planetary photography would
be made easier. not sure just thought I would throw that one in.
#Note: Remember when using this device
you must first turn your hand held switch off, lock your cable
release down, turn on the cameras power
switch and then your ready to shoot. Also I should mention the
camera I used was Pentax P30t. One
more thing the penlights will give you over 1000 hrs of Deep Sky
photography.
Focusing
cameras for prime focus astrophotography has been accomplished in many
ways, but to me my method seems the simplest. The basic concept is to parfocal
a camera body to your highest magnification barlow, eyepiece combination.
To do this you need to come up with a 2" to 2" adapter by approximately
2" in length that if necessary can be cut down so as to allow fine focus
adjustment with the 2" to 1 1/4" adapter. Now would be a good time to explain
the actual procedure involved in parfocalizing the two. First you set up
your scope and point it at the closest object, telephone poles work great,
but be prepared to use an extension tube so as to reach focus, next attach
your 35mm camera and start critically focusing on say the threads of a
bolt on the pole. Having decided you are perfectly focused you then lock
your focuser and detach your camera. Now place your new adapter assembly
with the barlow and eyepiece into the focuser, moving the 1 1/4" adapter
up and down until a clean focus is reached, tighten the two set screws
and you now have a focusing tool. The next time you are setting up to do
some photography, just pop in the tool aim the scope at a very bright star,
do a critical focus lock up the focuser, and drop the camera on. Don't
even think about looking in the camera to see if it is focused, just frame
your object and shoot. Just thought I should mention the barlow, eyepieces
are not dedicated to the focusing tool, but when using them for a night
of observing don't forget which combination is used in the tool.
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