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alexch
20-04-2011, 08:40 PM
Hi All,

Still going through the data collected during the SPSP trip and most of it is rubbish - either not enough subs or out of focus.

The 40x15sec tarantula subs were quarter-decent (slightly out of focus) and I managed to make this image.

I am not convinced this is the right colour but used this as a reference:
http://www.eso.org/public/images/eso0216a/

Comments welcome on this one as I have a feeling the result is a bit soft and needs re-imaging.

22" SDM Dob, Sony NEX-5A, 40 x 15sec, ISO 3200

full size available here (4MB):
http://users.on.net/~che/img/tarantula.jpg (http://users.on.net/%7Eche/img/tarantula.jpg)

Cheers,
Alex

mill
20-04-2011, 08:50 PM
Looks good but a bit soft and noisy, try some some longer exposures to get rid of the noise.
5 minutes would be better at iso 800.

alexch
20-04-2011, 08:56 PM
It may need more subs, but I can't do longer than 15 sec on Alt-Az mount. However I'd say 40 subs would have been enough if they were in focus and I did not need to sharpen as much. What you see as noise on the full image are mostly sharpening artefacts.

mill
20-04-2011, 11:13 PM
The best thing you can do now is to get a wedge :)
It will help a lot with a alt az mount.

barx1963
20-04-2011, 11:52 PM
That would be some wedge!!;)

mill
21-04-2011, 06:45 AM
Yes it might be slightly problematic :lol:

gregbradley
21-04-2011, 07:50 AM
A remarkable shot for the exposure. I imagine focus is tough to do with this setup. You can try some deconvolution on this image to sharpen it a bit.

Greg.

TrevorW
21-04-2011, 10:45 AM
Who modded the camera Alex

does the Sony have a bulb exposure

alexch
21-04-2011, 11:00 AM
The mod was done by Spencer's in the USA.

It does have Bulb via IR, press to start and press to stop. I soldered the IR transmitter to a canon/pentax intervalometer from ebay - works okay.

TrevorW
21-04-2011, 11:19 AM
Thanks Alex

not heard of Spencers do you have a link to a website

also a shame they don't have a timed bulb or manual setting shutter release seems to have everything else from what I've read about the camera

strongmanmike
21-04-2011, 11:38 AM
For the type of imaging you are doing Alex I recon this is a fine shot, I have never been a noise-a-phobe unless it is terrible, the colours match your reference image nicely too. Imaging this way ie big aperture and lots of short exposures is much more productive than the way I and many others do it :rolleyes:. If you get the focus and other quirks down pat you can image plenty the way you do aaaaand your scope is easily turned into an amazing visual instrument to boot :thumbsup:

Of course you may have issues if you were to try and image with a camera and chip like mine ;)

Mike

alexch
21-04-2011, 11:42 AM
http://www.spencerscamera.com/index.cfm

alexch
21-04-2011, 12:21 PM
Thanks, Mike.
I am still at the very bottom of the imaging learning curve and try to maintain a healthy visual/imaging balance of at least 60/40 in favour of visual. I've got at least 10 years covered with visual and imaging plans :)

Cheers,
Alex

Mighty_oz
21-04-2011, 02:25 PM
Lol !! 10 years of plans ! That's some planning ahead :) Way to go Alex.

alexch
21-04-2011, 03:33 PM
If the La Nina sticks around for a while it may become 20 :)