Quick question re PHD..

[stefski]

Hi all,

I am dipping my toe into imaging after many years as a visual. I've got my imaging set up working, PHD (after a 20 minute calibration:eek:) starts guiding, but loses the guide star after a 2-3 minutes.....I must confess I was only experimenting this evening, as moon is 1st quarter, so I set things up quickly just to see if everything worked. My polar alignment wasn't very accurate (naughty, I know). So I was wondering, should the inaccuracy of my polar alignment significantly affect PHD's ability to calibrate and subsequently guide?

Cheers in advance:),

Stef

[johnh]

Stef calibration should not take more than 2 mins, you set the calibration steps so PHD does 20-40 steps to get to 27 pixels west then north so make sure your calibration is set to right time - you should see star move but only slightly each impulse.

If you are not polar aligned then PHD spends its time correcting the N/S and may lose if the drift is to quick so you need good but not perfect PA.

John.

[stefski]

Cheers, John....Just as I thought!

Stef

[Tim]

I knew it Stef I knew you'd succomb to the lure

Have a read of the PHD gumpf, it will help you decide what to set your calibration step size to.

Also, for practicing, choose a star well away from the NCP to guide on, the more they move, the quicker you'll get setup.

[stefski]

I knew it Stef I knew you'd succomb to the lure

.

..There can be no escape!