Cheap astrophotography dreams

[johnridley]

With the unexpected (by me) success of the Canon Digital Rebel in taking wide field astrophotos at relatively long shutter speeds (several minutes), I'm thinking it's time to build a tracking platform for the camera. Typically this has meant a "barn door" tracker. I may just go with that, but one of the problems with a barn door tracker is that it does have some tracking error because it's not a true tangential mount.

I have been toying with the idea of using a microcontroller to drive the steppers, and then I could vary the speed as needed to eliminate any tracking error.

However, it also occurs to me that it shouldn't be that hard to do a true tangential drive with a plywood circle segment. I've seen things on the web of people who have made worm drive gears by applying J.B.Weld to the edge of a wood circle and imprinting a threaded rod onto it.

I will probably still use the microcontroller to drive the stepper motor, because it's just easier and less parts, plus I'll be able to microstep using PWM. But I think I'll just try to build the damn thing first and worry about fancy drive systems later, otherwise I'll never get it done.

I'd like to have this done for the Perseid meteor showers later this month.

Comments

Canon Digital Rebel

[lindaatzarquon.livejournal.com]

Apparently Jeff's friend Terry Blake also had that camera.

Well, after Berzerker, his friend Dan (the guy who shot the propane tank with his rifle) bought one. :-)

Re: Canon Digital Rebel

[johnridley.livejournal.com]

It's a dangerous camera in that regard. I know of at least 2, possibly more instances where people played with one for a few minutes and bought one within a week. It's done everything I ask, and then some. My 'reject' rate on photos from this trip was extremely low, owing to the ability to boost the ASA up to get non-blurry shots in low light conditions when needed, and the rapid shutter button response, which meant I got the shot instead of taking a picture of what happened 3 seconds later.

Re: Canon Digital Rebel

[ex-erikvolso370.livejournal.com]

Yeah. My brother has one. I'm still holding out for the soon-to-be Minolta Digital Maxxum, so that I can use the Minolta glass and flashguns I have, rather than having to bail and buy all new gear.