Tracking comets

[symesie04]

Just a quickie, i would like to do some comet photography and track using a Astrotrac, however obviously the standard star tracking rate is no good. So that leaves either the lunar or solar tracking rates, any idea which is best suited to comets? 

[Starlight 1]

Look on eqmod web-page I think you see one there.  Astrotrac you use eqmod if not may still help on speed for tracking.

[Starlight 1]

I did see a post not that long go. saying he use a program to work out were is was going to be at a set time , set up in this place a set cam rolling just before the time it was coming past.

I am trying to say is from a program point A to point B take so long you can work out speed.

[michael.h.f.wilkinson]

If exposures are short enough stellar tracking rate is the best guess. There is no reason lunar or solar rates should be better. Guiding on the comet's core is really the only option for improvement

[symesie04]

Interesting cheers gents. Cant say ive attempted to giude the astrotrac yet or anything else for that matter. And have no idea if it even supports EQMOD. Will have to have a Google. In the meantime short subs it is although at 400mm im not sure that will work either.

[michael.h.f.wilkinson]

At 400 mm I used 7.5 minutes exposure on 800 ISO Fujichrome. The core was rather blow out but the plasma tail showed decent detail. A 200mm shot of Hyakutake at 5 minutes was also OK. Sideral rate seems to work for quite some minutes

[Psychobilly]

For comets against a static star background I used to use shortish exposures if it was in close and moving a bit  and then do separate comet  and star stacks in DSS...  

I used to  guide on the comets core to produce movies of the comet moving against the background stars if it was passing something of "interest"... 

EQMOD isn't an option for the Astrotrac...

Peter...

[symesie04]

Thank you gentlemen. When time and skies finally combine i will give it a try sideral tracked on short exposures.