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Value of Astro-Physics RA encoder on 1600?

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#1 Aquarist

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Posted 14 February 2013 - 11:39 AM

Is the value of the RA encoder only for imaging? Recommendations? RA only or RA and DEC?

Thanks in advance.

#2 CarolG

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Posted 15 February 2013 - 02:07 PM

I'm glad you asked this question, Steve, as I too would like to know if the encoders are really worth the extra money, and if one encoder is more important than the other.

#3 orlyandico

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Posted 15 February 2013 - 02:12 PM

IMHO the RA encoder is probably good enough.

I feel its primary uses are (1) long-exposure unguided imaging, e.g. 30 minutes? 1 hour? and (2) it serves as a homing sensor for remote operation. To get full homing on both axes you'd need both encoders. Far more expensive than some little micro-switches..

I am not sure how much of an improvement to the unguided imaging is possible with the encoders; after all any CP3 mount with an S chip "supposedly" can do 20-30 minute unguided long exposures with the mount modeling in APCC. So would that mean 1 hour+ would become possible?

#4 Footbag

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Posted 15 February 2013 - 02:46 PM

I am not sure how much of an improvement to the unguided imaging is possible with the encoders; after all any CP3 mount with an S chip "supposedly" can do 20-30 minute unguided long exposures with the mount modeling in APCC. So would that mean 1 hour+ would become possible?


I hadn't heard that. Are other users getting long un-guided exposures with APCC?

After initially being enthusiastic about APCC, I realized it wasn't going to help my portable setup so much. When I finally go permanent, I'll probably pick it up.

#5 orlyandico

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Posted 15 February 2013 - 02:49 PM

Adam, Ray mentioned on the AP forum that with APCC even an encoder-less CP3 mount would be able to go that long (20 minutes+). Not sure how consistent it would be. It's one thing if 20 minutes is unreliable and the encoder makes it super-reliable. And quite another if 20 minutes is reliable on an encoder-less mount - leading to the question what extra would you get with the very pricey encoders.

People use encoders on lower-end mounts to improve the PE and tracking (e.g. TDM, SiTech) but the AP mounts have such low PE already.. an encoder would still improve it, but going from say 0.8" to 0.2" is not as dramatic as 10" to 1".

#6 Aquarist

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Posted 15 February 2013 - 05:23 PM

Ah, I should have specified that I am in a permanent mount situation. I have one on order and was considering the RA encoder only.






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