Orion Nebula - Version 1.0

Started Jan 21, 2013 | Discussions thread
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BobORama
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Orion Nebula - Version 1.0
Jan 21, 2013

I have an time lapse project I'm working on.  It will require a pretty "standard" time lapse of an industrial site.   But I want to do some garbage matting to add a star field to get the look I'm after   So I have borrowed an old, neglected Criterion Dynascope RV-6 motorized mount.  The motor drive has needed some attention, and has been an iterative process.

But tonight is the first night where I was able to get fairly reliable results.   The drive was working somewhat, and alignment is roughed in, enough to get 30 second exposures with a 300mm lens.

Here is what I got without much effort...

Stack of 4 of the better images, as shot.

100% crop.

The clutch in the motor drive is rather twitchy at this point, and tends to slip, which really reduced the number of acceptable shots to about 30%.   I plan to refurbish the clutch and that should improve this greatly.   The polar alignment is slightly off, causing some drift, but I'll get to that eventually.

The A* 300 is fairly sharp, but suffers from rather unpleasant coma and is hard to focus to infinity as it focuses past infinity for some reason..   When I have the mount in better shape the soligor C/D 650mm may do a better job, even though its a terrible lens otherwise.

BTW, in terms of seeing, the above is about as good as we get here in the middle of the 'burbs.

 BobORama's gear list:BobORama's gear list
Pentax K-5 Sigma 10mm F2.8 EX DC HSM Diagonal Fisheye Pentax smc DA 18-55mm F3.5-5.6 AL WR +8 more
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