It is currently Sun May 27, 2018 3:44 pm

All times are UTC




Post new topic Reply to topic  [ 1 post ] 
Author Message
 Post subject: What to do on a braw bricht moonlicht nicht?
PostPosted: Tue Oct 15, 2013 11:09 am 
Offline
Member
User avatar

Joined: Mon Oct 12, 2009 6:47 pm
Posts: 1250
Location: Bolton
When it's clear(-ish) but the sky's too bright for deep-sky imaging, I sometimes try for a planetary image. But as none of "the usual suspects" (Venus, Mars, Jupiter or Saturn) were visible last night, I decided to give Uranus a try.
I'd made one attempt at this planet some years back, but with it being so much fainter than the others, I couldn't get a bright enough image onto my webcam's sensor. However now that I've modified the camera for long exposures, I could have another go.

The main difficulty in imaging planets at high magnification is the seeing - the turbulence in our atmosphere. And with Uranus being relatively low in the sky (only 27 degrees above the horizon at 9pm), I'd be looking through quite a thick column of air. The usual technique is to take very short exposures (less than 1/30-sec) to try to "freeze" the brief moments of good seeing, but with exposures of >1-sec I couldn't do this. Nonetheless, I captured a few sequences of 300 images (as .AVI files) over 1.5 hours - the results got steadily better as the air in my telescope tube settled and the planet got higher in the sky - but then it started to cloud over. :(
All I'd managed to capture was a fuzzy blue disk, so I decided to try the planetary registration functions in IRIS for a change (rather than RegiStax). It was soon apparent that the Blue channel was suffering more dispersion than the red or Green, so this was all I managed to salvage:
Attachment:
File comment: Stack of 100 (best of 300) 1.1-sec images from my LX webcam, processed in IRIS
Uranus 14_10_2013.jpg
Uranus 14_10_2013.jpg [ 3.25 KiB | Viewed 2488 times ]

Well, it's clearly showing a disc, and some colour - and it's my first image of this planet. 8-)


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 1 post ] 

All times are UTC


Who is online

Users browsing this forum: No registered users and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
cron
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group