Astro at F2.8 - The Pleiades Star cluster


Mongoose

Link Posted 12/11/2007 - 22:21
I've been trying to get a half decent shot of the Pleiades for a while now with my various telephoto lenses. 200 M series F4, 300 Tamron F5.6, all tried and largely failed.

My new Tamron 300 F2.8 was bought partly with astro-photography in mind, and when I turned it on the Pleiades this Sunday night I was not disapointed.

This shot is the result of 19 stacked 1 minute exposures at ISO 800 and F2.8.




The stars are passing through a dust cloud, which we can see here as a blue glow around the stars.
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but it does help

iancandler

Link Posted 12/11/2007 - 22:33
thats pretty darn good.. what mount where you using??

Mongoose

Link Posted 12/11/2007 - 22:53
Thanks Ian,

the mount is a Celestron german equitorial which came with my Firstscope 114 short tube Newtonian. Actually more acurately the telescope came free with the mount, since it was really the mounting I wanted! It has a variable speed RA motor drive. My Dad and I have improved it somewhat, with a home made adaptor to take a camera instead of the telescope and an old Pistol scope for polar alignment. The scope has really made a difference, I am now able to get it set up for 1 minute exposures at 300mm easily, and have managed 3 minutes with a little work.


I was starting to get some passable results with my old Tamron 300 F5.6, but the F2.8 lens has made all the difference and this one I'm really pleased with.
you don't have to be mad to post here



but it does help

iancandler

Link Posted 14/11/2007 - 18:25
Yes the extra light grasp of the f2.8 really makes a difference doesnt it.
I cant wait to get my celestron CG5 up and running (waiting for a pier to be installed) M42 and M45 will both be top of my list as winter targets

Mongoose

Link Posted 15/11/2007 - 13:09
the CG5 is a nice mount, my Dad has a C8N on one though we don't have a pillar. Strangely the RA motor on the CG5 seems to work better if you unplug the Declanation motor. Can't explain why, and it might just be an idiosyncracy of Dad's mount, but it took us ages to figure out so thought you might benefit from the info.
you don't have to be mad to post here



but it does help
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