Re: Typical Guided Performance of GM8G, GM811G, and G11
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Liam, A partial answer: The GM8 RA drive uses a ring gear with 180 teeth around it. The GM811 and G11 use a 360 teeth gear that is about 2x the diameter of the GM8 design.? The larger ring gear with double the teeth gives about twice the sensitivity given identical worms.? So for better accuracy and stronger payload the G11 and GM811 can outperform the GM8.?? Getting subarcsec with autoguiding is achievable.? It requires excellent polar alignment and other factors to be set up right.? That's the effort required but many people do that all the time.? The choice of scope matters too...reflectors must keep the mirrors unconstrained, and you gave to be wary of "mirror flop".? Refractors don't have that issue... triplets are now super good quality and optical coatings are generally fabulous.?? Have fun...hope this helps. Michael On Thu, Feb 25, 2021, 9:36 AM <Liam.J.Cheney@...> wrote: I am looking to setup an EAA rig for live stacking at outreach events (I am new to astrophotography). I am leaning toward using an autoguider to maximize the number of usable frames and allow for longer exposures (probably won¡¯t want to go beyond 4 minutes at outreach events). I am considering getting a Losmandy mount for this setup. Based on the datasheets it appears that the GM811 and G11 have better unguided tracking performance than the GM8. Does this translate to significantly better tracking when guided? What would be a typical level of performance for each of these mounts when guided? Is it reasonable to expect sub-arcsecond performance from a guided GM8G? |
Michael Herman