Astrophotography

[robert]

My question is how do you get exposures longer than 30 secs without having too much "heavenly" movement.

Is there a cheap device that counteracts the earths rotation. I think they are readily available for telescopes but i only have a cheap telescope and dont want to spend much- just interested

thanks
Robert

[digitor]

You could make yourself a book mount http://people.rit.edu/andpph/text-star-tracker.html

Let us know how you get on!

Cheers

[robert]

Thanks digitor,
You got me on the right track- exactly the budget and simplicity I was thinking! I didnt even know what they are called.

After a bit more googling (search "barn door tracker" or "scotch mount") I found these in addition to the link by Digitor, for those interested.

http://www.angelfire.com/stars2/bwolfe/BarnDoor.htm

http://www.philharrington.net/scotch.htm

One more question- all of what I found said direct the hinge towards the north star- I assume for Southern hemisphere look for the south celestial pole, so how do I find it?

Thanks
Robert

[Analog6]

There is an excellent page on Wikipaedia on this. You use the southern cross.

http://en.wikipedia.org/wiki/Celestial_pole

[Jeko70]

Thanks digitor,
You got me on the right track- exactly the budget and simplicity I was thinking! I didnt even know what they are called.

After a bit more googling (search "barn door tracker" or "scotch mount") I found these in addition to the link by Digitor, for those interested.

http://www.angelfire.com/stars2/bwolfe/BarnDoor.htm

http://www.philharrington.net/scotch.htm

One more question- all of what I found said direct the hinge towards the north star- I assume for Southern hemisphere look for the south celestial pole, so how do I find it?

Thanks
Robert

Hi Robert
Do you know this little program: Cartes du Ciel (free)?

This program enables you to draw sky charts, making use of the data in 16 catalogs of stars and nebulae.
In addition the position of planets, asteroids and comets are shown.
The purpose of this program is to prepare different sky maps for a particular observation.
.......

Have a look here http://www.stargazing.net/astropc/

Enjoy

Fab

[glamy]

Here is an interesting link that explain the relation between exposure and aperture to avoid streaking stars.
http://www.luminous-landscape.com/tutorials/meteor.shtml
I find "Luminous Landscapes" a very informative site which I often visit.
Cheers,
Gerard

[Potoroo]

Those interested in some award winning astrophotography may care to check out http://www.martinpughastrophotography.id.au:80/.