Camera tracker

[8472]

Is there anything mount-wise on the market good for unguided imaging in the 300-400mm focal length range?

My Star Adventurer can only reliably image at that focal length with guiding. But If I want to guide, i have a proper GEM for that, (which takes too long to set up). I do love the unguided dithering feature of the Star Adventurer too, but I don't see another tracker that supports this.

The Astrotrac and Fornax Lightrack II seem perfect for my needs, but the deal-breaker is they can only image for 2 hours at a time, so useless for any meaningful unattended sessions (i would love to know if some genius in the astro community has modified one to run all night,  just like the Star Adventurer can).

I also like the look of the new RST-135, but not at that price!

[dph1nm]

5 hours ago, 8472 said:

I also like the look of the new RST-135, but not at that price!

According to another forum It has large inherent periodic error, so you really need to guide.

NIgelM

[pc387]

The Astrotrac 360 claims all night long tracking ability (at a price, and as yet not field tested by end users); not sure about unguided accuracy?

pc387

[8472]

2 hours ago, dph1nm said:

According to another forum It has large inherent periodic error, so you really need to guide.

NIgelM

Large PE with a harmonic drive? That doesn't sound good.

How is that possible with the way the gears engage?

[8472]

1 hour ago, pc387 said:

The Astrotrac 360 claims all night long tracking ability (at a price, and as yet not field tested by end users); not sure about unguided accuracy?

pc387

If it ever materialises, it might be too big to be called a grab and go tracker. Also seems overkill for my needs.

Happy to be corrected, though.

[dph1nm]

On 25/11/2019 at 16:46, 8472 said:

Large PE with a harmonic drive? That doesn't sound good.

As I read it, the main  benefit of harmonic drives is zero backlash. They still have periodic error, and as with most  mounts it would seem that the more you pay the better it is.

NigelM

[8472]

I think I'll stick to guiding my SA for now.

Thanks