Unguided tracking

[Guest dawson]

To see how good the tracking of the mount is, without guiding it, is there a standardised method?

I was thinking of just attaching the DSLR and doing a series of long exposures (1-20 minutes) and looking when trailing of the stars appears.

But what part of the sky, given apparent motion will be vastly greater in some parts than others.

Thanks

James

[Orion]

I think you can do the exposure for a period with the drive ON, then with it OFF.  If properly aligned, there should be a series of straight lines with arcs on the ends.  It would take me an age to find Ron Arbour's Sky and Telescope article, published probably 1987-1994?

 

I vaguely recall the length of the line or arcs gave an indication of the extent the alignment and hence tracking was.  You probably could do maths on the lengths of the lines (or arcs?) and convert that into the maximum unguided exposure you could do without trails.

[glider]

You can use PERecorder to record your periodic error and then analyse it using Pecprep.

[Guest dawson]

I wasn't thinking that complicated. Just a simple assessment of my mounts tracking abilty. I'll have a go at various areas of the sky.

Thanks

James

[glider]

It's free software and really simple using a webcam so you have all the gear.

[Guest dawson]

Ok, i'll have a look at that. Yet more software to install and learn how to use

Someone should write a software package that does it all!

James