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by JKCalhoun 1947 days ago
Did some Googling — apparently you can use Dobsonian for astrophotography.

Seems to me the field is wide open for someone to come in and solve it using off-the-shelf hardware. Maybe tapping the CCD and detecting the minuscule changes ... servo to rotate the CCD, servos to adjust pitch, yaw ... a feedback loop that blips the servos and decides if the image error is increased or diminished....
3 comments
dplavery92 1947 days ago
> Seems to me the field is wide open for someone to come in and solve it using off-the-shelf hardware.

Solve what?

You certainly wouldn't be the first to build a motorized tracking mount for astrophotography. There are plenty of existing products for manually-aligned star-trackers, and several still for "autoguiding" trackers that use the position of fiducials in the image plane. (These can use either a mirrored split in the optical path of the main imager "on-axis", or use a piggy-backed guidescope imaging system on the same mount.)

Check out high-gain, high-sensitivity imagers like the ZWO ASI290MM Mini, controller like the ZWO ASIAIR Pro, and tracking mounts like the iOptron CEM25P or Sky-Watcher EQ6-R Pro.

These are expensive, carefully engineered solutions, though. They don't really exist in the same market space as Dobsonian telescopes, and it wouldn't make any sense to make those tracking solutions twice as complicated and twice as expensive using by non-equatorial mounts.

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JKCalhoun 1946 days ago
I was unable to find a tracking solution for Dobsonian mounts. If they exist, awesome. I doubt a home-brew solution though would cost as much as the ones you identified.
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dreamcompiler 1947 days ago
I'm not surprised one can do it but it seems kind of silly, like using a motorcycle to pull a plow, or using a microwave oven to bake a cake. By the time you get it working halfway well, you could have just bought the right piece of equipment in the first place.
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gbrown 1946 days ago
This is already a thing (tracking + derotator+ ccd in alt-az), but it’s super expensive and doesn’t work as well as just using an equatorial mount in the first place.

More basic tracking dobs are used for planetary and lunar astronomy though due to the shorter exposure times.

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