Tonight the clouds cleared again and even though the moon was nearly full I wanted to test my new autoguiding setup.
A modded (read - cheesey hack job to a) 8x50 finder scope I had
sitting on the shelf. I hacked about 3/4 inch off of the end of the
tube to get the camera to come to focus. I used the 1-1/4 inch tube
from an Orion Variable camera adapter, wrapped a few layers of duct
tape around it to fatten it up and crammed it into the finder tube. It
holds the camera perfectly.
Monochrome Meade DSI Pro. I modded it by using duct tape to block
the sides where the filter slider goes in because I don't plan on using
the slider at all. I may find a more permanent solution to block the
The DSI Pro has about the equivalent of a 5mm eyepiece and in the 50mm finder is roughly 25 power with a 1 x 1 degree FOV.
I purchased a Shoestring Astronomy GPUSB and GPFC-14 cable (the
proper cable for my particular setup) as an interface between the
computer and the mount
Simply because it works with a Mac and it's free I started off
with PHD Guiding from Stark Labs as the guiding software. I was
pleasantly surprised at how easy it was to use and how spot on it kept
Invasion of [the] Wires
So now the scope setup looks really strange to me. I used to have
a scope sitting there. No wires or anything. Now it's got wires galore.
I went from having only a power cable going to the laptop to:
1) Power to the laptop
2) Power to the EQ platform
3) Power to the Sirius mount
4) USB to the EOS 350D camera control
5) USB to the DSI Pro guide camera
6) USB to the DSUSB shutter control box
7) Shutter control cable from the DSUSB to the camera
8) USB to the GPUSB autoguide control box
9) RJ12 GPFC cable from the GPUSB to the Sirius mount
10) USB to the Serial adapter for scope control
11) Serial from the Serial adapter to the Sirius scope controller
Since I only have 2 USB ports on my laptop I've got the multiple
USB devices going to a USB hub. I have a feeling though that I need a
powered USB hub because the DSI needs power over USB and it's not
getting it from the current hub. So there's a new power cable - number
12. Then I also think I need to get a power adapter for the EOS 350D
because if I'm going to take long exposures for hours at a time I will
eat up my batteries. I've already had a battery die twice in the middle
of a sequence. So there's cable number 13. Sheesh.
The Setup for the Test
In setting up for my first autoguide test I pointed the mount
North, put Polaris in the proper spot in the reticle and called it good
for the polar alignment. I then performed a 3 star alignment and turned
on Sidereal tracking. No leveling, drift aligning, PEC, or any other
The target was M35 for no other reason then it was near my last
alignment star, was opposite the moon and has lots of stars in it. I
only took 3 frames this evening and I threw the first one out. I wish I
would have kept it for comparison.
A 5 minute exposure with the mount as is. No autoguiding or PEC.
The stars were rather drifty. Elongated and definitely no good. As was
expected. I wish I wouldn't have tossed the frame.
A 5 minute exposure, ISO 800, with PHD Guiding controlling the
autoguider via a 6.7 magnitude star. PHD Guiding was set to 1 sec
See Gallery below for image
Since frame 2 worked out so well I thought I'd double it. A 10
minute exposure, ISO 800, with PHD Guiding
controlling the autoguider via a 6.7 magnitude star. PHD Guiding was
set to 1 sec exposures. This image was horrendously blown out in greens
and blues from the CA (I'm assuming) so it ended up being black and
See Gallery below for image
Needless to say I'm very excited about the potential here. If I can take 20, 5 minute exposures
at ISO 800 I think the quality of my images will increase substantially.