M42 with a $150 lens..

[Crushellon]

Went to my local JB Hifi on the weekend and saw the Sigma70-300mm f4-5.6 dg macro for $150.... needless to say I couldn't resist. I mean, for that price who cares if it's terrible I can still have some fun with it. So I took some photos that night, seeing was horrible, there was local burnoffs and the air was quite smokey. But all the same, my results were pretty good for a super cheap lens piggybacked on a goto dob.:)

Canon 550D
Sigma 70-300mm f4-5.6 dg macro @ 300mm f9.0
249 Lights 4sec iso1600
40 Darks
101 Bias

Hi Res: http://www.astrobin.com/full/245041/0/

[dimithri86]

Wow nice.

[ZeroID]

Impressive !!

Well done

[Camelopardalis]

Nice one Tim, doesn't get much fairer than that :thumbsup:

[astronobob]

Very decent result Tim :thumbsup:
Did you use a mount or just off a tripod, I assume a tripod, - very well executed :thumbsup:

[Crushellon]

Thanks, it was piggybacked on an alt-az mount.

[janoskiss]

Nice to see folks getting lovely results with budget gear! :thumbsup:

[Crushellon]

Yeh it's at the detriment of my cameras shutter though... I'm taking ~300 shots per target to get good results from the short subs. I need to lay off a bit until I get a heq5 and not overdo my shutter mechanism so much.

[janoskiss]

You could try Bojan's trick of using an external aperture stop instead of relying on the lens' built in one.

I missed the goto Dob bit in the OP. Yeah, that will give you field rotation if nothing else. You could also try and aim for targets in the sky where that's minimal.

[FlashDrive]

That's really nice....

Col...

[Crushellon]

Yes, have read about this once and am interested in trying it so I don't get the spikes on the stars but nothing I search comes back with relevant information and I don't even know what to look for.