Rig
This is the latest iteration of the imaging rig.
Now that there's a second digital camera in the house,
this photo actually shows the D70 in situ for the first time.
The main imaging scope is a Celestron 8" f/10 SCT, Kate. Kate has a Virtual View installed,
which allows the D70 to be rotated to help frame the photos.
Kate shares time with Veronica (the 8" f/5 Newtonian) as the main imaging scope.
Both Kate and Veronica have Robofocus motors installed, which makes focusing a much more straightforward task.
This photo was taken on the first night that Pumpkin, the new Astro-Tech 66mm f/6 ED refractor was installed as
the new guidescope, replacing Wobble, the venerable ST80 refractor that I'd pressed into service in 2004.
Pumpkin will spend most of the time as a guidescope, but will occasionally get used as an imaging scope,
mostly for the small handful of giant DSO targets, like M31, NGC7000, the Veil Nebula, etc.
Wobble didn't make a good photo scope, but Pumpkin is turning out to be not too bad.
Wobble has been turned into a spotting scope, and will be used primarily for camping.
All of this is atop the new (to me) Losmandy G-11 mount, which has really pushed my astrophotography
capability into new territory. It's ever so much more stable than the CG-5GT that it replaced.
This is Pumpkin, the Astro-Tech 66mm ED refractor, on the first day with guidescope rings.
For reasons passing understanding, this particular set of Losmandy guidescope rings
is matte silver instead of black anodized.
Doesn't seem to hamper their effectiveness, but it does throw off the all-black mount motif.
Not that Pumpkin really blends in, either.
The G-11 does not have a GOTO computer like the CG-5GT had, so I started out using manual setting circles.
Despite complaints that you'll hear about setting circles, this is actually quite an effective method of
pointing the telescope. With Veronica as the imaging scope, I could center up a single star, set the circles,
and then point the scope to pretty much any target I wanted, and still get it in the field of view of the camera.
When I moved to Kate, the extra magnification started pushing objects just out of the FOV, which left me needing a
more accurate method of pointing the telescope. I found the Dave Ek Setting Circles Project online
(thanks, Dave!) and I put together the parts to make myself a setting circles interface. These are all the parts, ready to be
assembled and put into a project box. After finding out that one of the encoders on the mount was blown and getting a
replacement from Losmandy, I got the setting circles interface up and running. Still trying it out, but it seems good so far.
This is an updated photo of Rig now installed in the Ad Astra Observatory at Newark.
This is a great little device of my own invention; it's a "smart" IR remote control for the Nikon D70.
I set it for exposure length, exposure count, and delay between exposures, and just walk away.
The little box takes care of the rest. Saves having to run a laptop all night, plus it was really fun
to learn how to program PIC microcontrollers in order to build it.
This is Rig when it lived in my backyard in Brentwood. The skies were darker there, but Rig is in much cushier accommodations now...
Centered around a Celestron CG-5GT mount and SBIG ST-4 autoguider,
shown here is the ED80 main scope, ST80 guide scope
, and piggyback mount.
The setup can include 2 imaging cameras; an SLR mounted piggyback and/or
an SLR at prime focus of the ED80.
This is a detail of the tube rings, showing the main scope mounted to a dovetail,
with guidescope rings atop those. Note that the piggyback rig was mounted to the
guidescope, a feat of engineering with the short tube of the ST80.
This is a detail of my piggyback mount. I am using a Bogen 3262QR ball-head mount.
I like this mount a lot. It holds well, and it's very easy to position.
This is a detail of the ST-4 and the prime focus imaging camera. Note that I'm using
the shaft of a 3x Barlow as an ad hoc extension tube to allow me to run the ST-4
straight-through. This helps a lot with getting the rig balanced, and also keeps
things from flopping around, as they might if I ran with a diagonal. I wrap the
ST-4's cord around the base of my finder, as a safety measure.
For lunar and planetary photos, I use a Logitech QuickCam Pro 3000 webcam. I bought
a Mogg adapter to allow the webcam to be used at prime focus.
This is a detail of the focuser on the ST80 (now used as a guidescope), showing the
stock T-threads. The ED80 came with a similar setup on the stock 2"-to-1.25" adapter,
but I replaced that with a 2" T-adapter, to reduce vignetting.
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©2004 Jimbo S. Harris