It became increasingly clear that in order image the Polaris region with my Canon
EF 200mm f/2.8L II USM that I would have to use an autoguider. There are of course several different ways to go about this, however, I wanted to make another easily removable, modular, stand-alone setup so I decided to build a bracket out of a leftover piece of an aluminum plate used to build my main scope gadget holder (
https://astroquest1.blogspot.com/2019/06/the-pegasus-astro-pocket-power-box-best.html) that secures may Pegasus Pocket Power box among other things. There is room to switch out the camera at a later date if I choose too. This bracket attaches to any dovetail type telescope mount but can also be attached directly to my telescope rings.
Parts:
1) 1 -
Vello Camera Ring Holder
2) 1 -
8-in dovetail bar
3) 1 -
4 x 8 x 1/4-in aluminum plate
4) 2 -
ZMAX 18-Gauge Galvanized Steel Angle
5) 1 -
50mm autoguider telescope with bracket
6) 1 - Canon T3i (600D)
7) 1 -
Canon EF 200mm f/2.8L II USM
8)
various length 1/4-in #20 nuts and bolts
Construction Summary:
1) Cut aluminum plate to size, 4 x 8 inches (10.2 x 20.3) cm
2) Cut two additional aluminum pieces from plate for spacers, 1 x 4 inches (2.5 x 10.2 cm) - optional
3) Position camera* and guider for proper balance and mark drill holes
4) Drill holes with 1/4 inch (6.3 mm) metal drill bit into the aluminum plate and spacers
5) Cut Galvanized angles so they don not overlap (optional)
6) Check to ensure bolts line up
*NOTE: leave room for accessing the camera battery holder.
The Two small plates used for spacers were placed between the main plate and the dovetail bar. The were needed because the Sirius mount screws hit the bottom of the plate without the spacers. If I use the Atlas mount the spacers are not needed but no reason to remove them.
Test:
I did a preliminary test using the Ring Nebula region in Lyra. I used this because there was not anything bigger in my viewing window plus I was mainly interested on how the stars looked anyway. I was on this object for 30 minutes and with no drift and this is the most round the stars have ever looked using this lens so I think I am ready for some more interesting objects in the future. The image is was made with 21 x 45 sec subframes and what 30 minutes of processing can do.
M57 - Ring Nebula Region, Lyra
Location: Home Monroe, CT
Date: 7-6-20
Camera: Canon T3i/600D modified
Lens: Canon EF 200mm f/2.8L II USM
Focal Length: 200mm
RGB f/3.5
Mount: Orion Sirius
Autoguiding: QHY-5II attached to an Agena 50mm Guide Scope with Helical Focuser
Exposure: 21 x 45 sec
ISO: 800
Temp: 17 C
Processing: APT, BYEOS, PixInsight, Photoshop
