Polar Alignment - Does anyone do it this way?

[Alestrom]

I read on a website somewhere of a way to polar align using exposures, but I've never seen it described anywhere else. Does anyone else do it this way (I've adapted it slightly)?

1) Align initially as best you can visually etc.

2) attach camera and orientate with the long axis of the frame east/west.

3) find a suitable star in the south/ease to align azimuth/altitude and place towards east of frame.

4) expose for say ten seconds with tracking on, then at double speed for the length of exposure you are planning to take. Then turn the tracking off and leave for the same length.

5) you get a 'V' shaped star trail with a 'blob' indicated where you started. The 'north/south height of the V shows the amount of drift.

6) adjust and repeat accordingly.

For some reason this method gelled with me, I had tried drift aligning with a reticule eyepiece but never really felt I got anywhere (I've only just started imaging anyway).

Any thoughts anyone?

[David Galvin]

I have tried this method with several mounts, German Equatorial and Fork mount and found it to be reasonabley accurate, quick too. I should add that I always check with the drift alignment as I am a little stuck in my ways.

Polar Align - No Drift

[Alestrom]

Fair do's

I think I was lucky the first time I tried it, as I got straight line rather than V's with no adjustment, so I must have got close visually.

The second time only one adjustment and it seemed to be there - it does seem a quick method.

Maybe next time I will be unlucky and it will be no quicker than normal drift alignment.

[David Galvin]

I think it would be useful for those who have 'Polaris' obscured and struggle to polar align. I must give it another go as it has been a while since I used this method. :-)

[dark knight]

Now that looks well worth trying, think I'll give it a go, thanks...

Carl

[Alestrom]

I certainly found it easier, it just seems more systematic than staring through a reticule. It has the advantage of not having to attach the camera after drift aligning (I don't have a guide scope)which could jog the mount and which I find is fiddly enough in the dark. Also you're aligning with the same magnification as the imaging, if the camera doesn't see the drift you know you're there and you can extend the exposure in accordance with the subs you're planning to take.

I've only just started imaging so I don't know if all the ins and outs yet...

[dark knight]

Well i'm sure my polar alignment could benefit from this method. I think because you get a piccie of the result it seems more reassuring...I always have major doubts about my polar alignment...

[themos]

I use EqAlign. It knows how to drive ASCOM or LX200 telescopes but you can use it with any telescope. It needs a webcam. Each drift run should take 10 minutes. At the end of each drift run, the webcam view is annotated with circles telling you where to put the target star (using RA/DEC controls) and then where to take it to (using elevation/azimuth controls for the polar axis).