This weekend we experienced a fairly rare event in Waterloo: A clear night sky combined with a new moon! This meant that Aravind and I could go out and try all of our new stargazing equipment. I figured this would be a good time to test out a little project I've been working on for the past six months: Mike's AstroTracker Mark 1! If you haven't heard, it is my attempt at building a software-controlled "barn door mount" (or "scotch mount") that will allow me to take long exposure photos of the sky without having to invest in expensive equatorial telescope mounts. Anyway, I dusted the cobwebs from my creation, charged up the batteries, and spent a couple of hours writing a quick little control application for my laptop.

Unfortunately I was so focused on pulling it all together at the last minute that I forgot to charge the batteries in my camera. Since I took so many pictures last week at Blue Skies my batteries were almost dead. In fact, unbeknownst to me, after taking this picture I only had enough battery power left for two more photos. So, after packing up the car and driving for 45 minutes to get away from the city lights, we found a good spot to set up between two cornfields and I set up my spiffy new AstroTracker. I took two test shots to make sure it was stable, and then gasped in horror as my camera shut off.

I guess that's just the way it goes. My two test shots did provide me with some data though... it looks like the AstroTracker Mark 1 will be stable enough to do wide field astrophotography. After reluctantly packing up my stuff I helped Aravind take some photos with his new camera and telephoto lens. His camera was piggybacked onto his telescope. While you are here, take a look at the pictures he took that night. They turned out surprisingly well! The main artifact you may notice in his photos is that some of the stars are streaked in a circular pattern. This phenomena is called field rotation. My AstroTracker mount will not suffer from this problem... it's too bad I couldn't get any photos to demonstrate it! Anyway, Aravind will probably buy an equatorial wedge for his telescope to eliminate his field rotation problems as well.

Comments

sucks to be you, buddy!  bummer about the batteries.  next time, eh?  aravind's
shots look pretty cool... but you can really see the streaking once the
exposures get up above about 100s.  looking forward to seeing your invention in
action!

also, any idea of total materials cost, or time invested in your
mount?

I tried to keep the materials cost under $100.	I don't think I succeeded, but
then again I did buy all new parts, and none of it was on sale.  I kept all of
my receipts so I can do a final tally later.

Most of my time was spent
learning about the parallel port and stepper motors, and then fumbling my way
through the design and implementation of my control circuit.  I plan to write
up a full website detailing all aspects of the construction once I have some
photos to prove that it works.	;)