7awol Loc: Butler, Pa

Prior to purchasing the Ioptron Skytracker Pro, http://www.uglyhedgehog.com/t-455608-1.html, I fabricated a Barn Door Tracker from plans that I found on the internet. http://barn-door-tracker.co.uk/ Up to this point, 22 second exposures were my max before star trailing reared its ugly head. I'm using a 24mm Rokinon on a full frame Nikon D700 for my wide night sky photos. Great fun building and learning...especially about neat things like "sidereal", "right ascension", "declination", Polaris and the Celestial North Pole. First light results were impressive to me. Stars stayed round and crispy when I did a good job focusing and aligning. Alignment became easier and results improved after adding the Telrad Finder Scope ($40). Instead of using wood to build the "doors", I used some leftover 6" wide PVC Decking. Works great, looks nice, doesn't warp and can be "whittled" with regular woodworking tools and techniques.

The attached image of the belt area and M42 in Orion was made with the barn door in January. I used my Nikkor 70-200 f2.8 lens on the D700. The lens was set to 135mm, f2.8. ISO is 1600 and exposure is one minute. I made 12 images, 8 made the cut and were stacked in Photoshop CS3 for noise reduction.

Dean

(Download)

SonnyE Loc: Communist California, USA

Very nice Dean!
And shows it does in fact work.

I like the Polar Alignment on the "door"
I was able to readily find Polaris for alignment using the big dipper while camping.

dlmorris Loc: Loma Linda, Ca

Very nice. I built a barn door tracker some time ago as a demonstration of simple trackers, and like you, attached a telrad for alignment, and it does indeed work quite well. Mine uses a curved 1/4-20 threaded rod, and a CD with notches which you must adjust every 5 sec. But it does work! You did good!

bwana Loc: Bergen, Alberta, Canada

I built something similar to this back in the '60's for a science project in high school. Used a "modified" Brownie camera, 620 film, to prove that the idea worked. The black and white pix weren't all that great but the project got a passing grade...

bwa

7awol Loc: Butler, Pa

Thank you...the Polar Alignment graphic was made using the night sky centerfold from a Sky and Telescope magazine as a template. I used different size drills, trying to represent the magnitude of the stars. Drilled about 1/8" deep and filled them with "glow in the dark" paint from the local craft store.
Dean

7awol Loc: Butler, Pa

dlmorris...upscale, using a curved threaded rod adds an additional construction challenge. Good for you! Besides looking cool, your tracking accuracy will be better than mine. I downloaded a 5 second beeping timer into my IPhone to keep me on track. The Telrad is a good little gadget, not only as a Polar alignment aid, also helps find celestial objects. Sky and Telescope has a scaled Telrad reticle printed in their Sky Atlas that is designed to help us navigate by "star hopping".
Dean

7awol Loc: Butler, Pa

bwana...Wow, sounds like you got way more than a passing grade if you are still "looking up" 50+ years later! Neat stuff. Thanks for sharing.
Dean

Ronsh Loc: Floresville,Tx.

How do you like the star tracker pro?

7awol Loc: Butler, Pa

Only a couple of sessions so far...both competing with a big moon and light polluted skies...see here
http://www.uglyhedgehog.com/t-455608-1.html
Tracking results have exceeded expectations, even at 200mm and one minute exposure.

Hoping to get to Cherry Springs State Park near Galeton Pa (best dark sky area within 500 miles) during the New Moon.

Will share results.

Dean

bwana Loc: Bergen, Alberta, Canada

Still looking up and still chasing the perfect astro-image... But I definitely find it much easier with today's digital cameras. No more waiting a week+ for processed photographs to come back by mail!! A good reason to set up your own darkroom; excellent repurposing of an unused bomb/fallout shelter! And yes, being between the USA and Russia, Canadians also had these.

bwa

7awol Loc: Butler, Pa

Bingo!