Guiding Near the Pole

[iksose7]

I was out under a clear dark sky last night, first one in a week or so and no more forecast for any time soon.

I really want to attempt a nice deep image of Polaris, possibly showing some of the galactic cirrus clouds floating in the area. So thats what the plan was. 

But i just couldnt get PHD to calibrate, it would get to step 61 then fail (the old 'not enough star movement') 

I know that guiding around the pole is probably the hardest area of sky to track, so i was wondering if anyone ha any experience with this and can offer up any 'tips, trick or techniques'?

Once i'm calibrated i'm thinking it may not be too difficult to guide as i'm only imaging at 200mm but i may be wrong. But i spent a good 90 minutes last night messing around, then gave up and slewed over to Cygnus where PHD calibrated 1st time. So its obviously struggling being so close to the pole.

The only thing i can think of is to maybe turn my guide scope 90 degrees to the left (pointing West where it should calibrate) then hope it would produce pin point stars on the DSLR pointed at Polaris. But i have a feeling this wouldnt work due to stars in the West appearing to move at a different rate to those closer to the Pole?

I'm very new to guiding to i hope i'm not making some simple error, hopefully someone could chime in with a strategy here?

[Owmuchonomy]

Hi. What durations did you use for the calibration steps? If you are getting not enough movement errors then step up the time duration. Mine can vary between about 800 and 3000 ms depending upon target (and FL).

[iksose7]

Hi Chris, 

I tried 1500-3500 in 500 step increases. No luck!

[Steve 1962]

Hi Callum

As you've already identified - do you need to guide at all in this situation? 

Your idea of off setting your guide scope seems like a good one, but 90 degrees sounds excessive - it would work all night if you choose a circum polar star - I'd stick within 20 - 30 degrees.

Steve

[iksose7]

Hi Steve,

Yes guiding is needed i'm afraid. I'm lucky if i get a 180 second sub without it!

And yes, you are right 90 degrees is a bit much. So you reckon point the guide scope 20-30 degrees to the left? Just checked my forecast and it has changed to clear the next 3 nights! The weather this year is all over the place. Look like i will get a chance to try this tonight.

[Steve 1962]

Hi Callum - I'd see how close to pole your calibration will work and use that - Trial and error I'm afraid!