Is Drift Alignment and Periodic Error Correction needed when using auto guiding?

[Lrlinnell]

If you are using an auto-guiding scope and ccd with PHD, do you need to worry about drift alignment and/or periodic error correction of the mount?

 

[alacant]

Hi. Yes. Every little - no matter how little- counts. If you have to choose one or the other, go for drift. HTH.

[bobro]

An autoguiding setup will ensure the guide star remains central. However, depending on the relationship in the setup between the guide star and the imaging view, field rotation can happen, resulting in star trailing. If polar alignment is very good it will reduce/eliminate field rotation and produce less/no star trailing. So yes, polar alignment is important - especially as exposure length increases. Drift alignment is a very good way of polar aligning.

PEC, being a predictive method of correcting errors before they happen, helps reduce star trailing and is particularly applicable to a non-guided configuration. Autoguiding also reduces star trailing by correcting errors as they happen. Arguably, PEC is less important when autoguiding as errors will be automatically corrected anyway.

[Lrlinnell]

OK, so since I want "every little bit" drift alignment + auto-guide (plus PEC every once and a while as gears age)

Thanks, this forum is awesome! I would not be able to be in this hobby without your help and advice.

 

Lloyd

 

[richyrich_one]

I found that trying to use PHD to drift align erratic and PA error kept fluctuating.

I suspect this was due to not using PEC.

My plan is to record the PEC first, then drift align, then guide.