Thanks to some help from the Google+ astronomy community, I’ve been getting some pretty decent results imaging Jupiter. I’ve found that my Canon t2i 550D in movie crop mode works amazingly well for capturing video with just a 2x Barlow and my 10″ Dobsonian.
2012-10-03, Jupiter “back side,” not showing the Great Red Spot, RGB data shown
2012-09-27, Jupiter showing Great Red Spot
2012-09-23, LUCKY Jupiter image showing the Great Red Spot and a moon shadow from a Europa transit
OH, YEAH…the video source!
Recorded with a Canon t2i 550D in movie crop mode + 2x Barlow on a Zhumell Z10 Dobsonian, on my DIY EQ platform for tracking.
Hi Cory, what a great website you have! I am like you, trying AP with a 10″ Dobsonian on an EQ platform. In my case, I built a motirized barndoor platform and believe it performs about equally well as yours. What is nice about the Jupiter video is that it lets us estimate the drift of your system. I estimate it at 0.1 Jupiter sizes per 10 s which is 0.000133 deg/s. For a typical F/4.5 f=1154mm 10″ Dob and a Rebel XT sensor of 16.4mm diagonal at prime focus, the FOV is 1.32 degrees. The required accuracy for AP is about 1/500 of the FOV diagonal, which is 0.0026 deg. For a 30 s exposure and the above drift we get 0.004 deg which is only a little above that boundary. So, our systems should be good for 30 s exposures if we toss about the 90% of the pictures with too much drift. Based on that and on the fact that the longer term drift is not that big, I think all we need to get professional looking pictures is to add a second axis, a guide scope and run PHD on it. PHD will perform corrections within a few seconds so that ought to allow us to use exposure times as long as the best commercial platforms out there. We are real close! I posted a reply to your EQ platform thread on the astronomy forum but I don’t think you are checking that regularly. Keep plugging away, your results aree real nice. All the best – Henk.