First time auto guiding with PHD

[naskies (Dave)]

Despite the crazy moon glare last night, I tried auto guiding with PhD for the first time last night using the Orion Awesome Autoguider package on my NEQ6.

I started with my Canon 5DmkII and a 200 mm lens on a side-by-side saddle adapter with the Orion to ease into it (and save set up time setting up the scope).

Drift alignment was HEAPS faster using PHD than waiting for a visible drift... I like the virtually instant feedback Auto guiding accuracy seemed to be pretty good at the tail of Scorpius when it was relatively high in the sky - here are three 100% crops from a stack of 3x 5 min exposures... perfect alignment as far as I can tell.

However, I do have a couple of questions that I was hoping the more experienced could help me out with:

1. On my NEQ6, in order to use the azimuth adjustment knobs, I have to release the tension on the centre bolt a little bit - which means the mount tilts forward a bit. After I use PhD to adjust polar alignment in the azimuth direction, I re-tighten the centre bolt... but then the polar alignment goes a little out of whack again. Any tips to reduce frustration / speed up the process?

2. I tried taking a long exposure photo of the SMC but I couldn't pick up a bright guide star nearby (bad light pollution where I live) - the shortest suitable exposure for PhD was about 1-2 seconds. However, guiding accuracy was quite poor - star trailing was visible on even 1 minute exposures. Was my polar alignment out, or are there certain settings I should be using in PHD? I was a bit perplexed considering that the other shot near the tail of Scorpius was so accurately tracked.

Thanks!

[Alchemy (Clive)]

1. Sounds like you will have to judge how much it will move when you tighten it and allow for it.

2. Could be lots of reasons, poor alignment always causes issues around the poles, when you calibrate phd you need to pay attention to which side of the meridian you are, when you flip you need to recalibrate. 1-2 secs would be the most common guide time so no big issues there. You also need to check where you calibrate phd it needs to be at right angles to the pole... Without getting technical, do it at the pole and it will fail in one direction and switch that component off.

[mill (Martin)]

1: smear a thin layer of ptf grease between the head and tripod and you can adjust without loosening the center bolt.

2: when imaging at the pole first calibrate with phd set at about 1500 ms steps so it does properly calibrate.

[naskies (Dave)]

Thanks guys - very useful tips. I'll give it a go when the weather clears up here.