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JB80
01-11-2013, 10:59 PM
I had other plans last night but instead got stuck on M45 so I thought I'd make a go of it. I tried it the other night with 30 sec exposures and wasn't happy with the results but last night used 1 min exposures and thought it turned out much better.
There is room for improvement but it's definitely my best attempt at M45 so I'm quite happy. The big bloaty stars I must try and fix though.


It's a stack of 121 one minute exposures.
At ISO 1600 and f/8.0
Taken with the 450D and 75-300mm zoom at 300mm.

cometcatcher
01-11-2013, 11:49 PM
Turned out reasonable.

Looks like the bloat is from CA. Stopping down further would help, but you would need more time to compensate.

JB80
02-11-2013, 12:09 AM
Yeah the lens is terrible at the longer lengths for CA, I had it at f/9.0 the other night and it was better but anymore and I'm going to lose too much light.

The other thing is I'm using the Polarie as the mount and I'm not certain just how long of an exposure I can go with the 300mm lens.
The manual states that at 100mm you should get 1min20sec so I don't think I can go much longer. I'll try it out though and see.

Rex
02-11-2013, 11:21 AM
Hi Jarrod, mate you've done well, for 1 minute exposures you have captured quite a bit of detail. Good luck trying to fix those bloaty stars, if you figure it out let me know. I occasionally use the same lense, although my images always have red fringes not blue. I have managed to improve them in the past but not totally remove them.

JB80
03-11-2013, 12:06 AM
Thanks Rex, I'd like to see just how long I can get out of this set up so hopefully I can go back to it with longer exposures later on.
I think it's just part of life with this lens, it can probably be managed in Photoshop.
Annies Actions has a process but the effect I see is not substantial.