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Fireball train

PostPosted: Wed Sep 27, 2006 6:46 pm
by Gordon
I'm sure its probably not what most of you are expecting! Its a fireball, as in a meteor brighter than Venus, and the glowing cloud of material left in its wake, known as a train. Image
Thats the fireball on the right, low in the northern sky. The orange trail is a plane that moved across the field of view over several frames. The animation is made up of frames taken over 10 minutes, 13 second exposures, at 15 second intervals with the D200. It shows the train being blown westwards by upper atmospheric winds, probably somewhere in the range 50-100km up.

http://www.mso.anu.edu.au/~gordon/Fireballtrain20060923GJG1.avi

The lens was a Sigma 30mm used at f/1.4, and I had the ISO set to 1600. The original images were small, fine quality jpgs, I normally use compressed RAW, but there isnt enough room on a 2GB card to keep exposing for the life of the battery, which was only 75 minutes. I think I'll have to get a mains adaptor and possibly some other external battery for when there is no mains power.
As you will see in the animation, I just cropped the lower right hand corner of the frames, so there is a bit of coma showing at f/1.4, but its quite good, much better than my old 55mm f/1.2 Nikkor.
I have made up some 302 frame animated gifs of the whole field, but at over 100Mb they are ridiculously large! so I'm not posting them
I used freeware called JPGVideo to convert the jpgs to an avi movie, which I hope most can view. It was made using Windows1 codec with a fair bit of compression to keep the file size down to 3.3Mb.
An avi movie of the 302 full size frames came out at 2.2Gb, and Windoze Media Player decided it wasnt going to play it :roll:

Gordon

PostPosted: Wed Sep 27, 2006 7:25 pm
by thelastname
Interesting and well done Gordon.

Movie works fine.

PostPosted: Wed Sep 27, 2006 9:06 pm
by Yi-P
Very interesting thing you can do with this.

Did you use a tracer/tracker device for the shots? Specially the 10mins exposure ones.

PostPosted: Wed Sep 27, 2006 9:18 pm
by Gordon
No tracking with these shots Yi-P, just using a tripod. If they were tracked the stars would not move across the sky as they do here, the trees would move the other way instead ;)
The exposures were short enough with the 30mm lens in that part of the sky to not show trails. Maybe my wording isnt clear enough in the original post- the exposures in the animation I posted are 13 seconds each, one taken every 15 seconds, for about 10 minutes total animation time.

Gordon

PostPosted: Thu Sep 28, 2006 12:29 am
by wally
We get some truly amazing stars down here in Adelaide!!

PostPosted: Thu Sep 28, 2006 11:40 am
by Laurie
Gordon, when was this picture taken?
reckon its related to this: http://www.youtube.com/watch?v=8mbA606ZRWI&eurl=

probably not :D (that was 22nd of Sep btw)

PostPosted: Thu Sep 28, 2006 2:59 pm
by Gordon
Laurie wrote:Gordon, when was this picture taken?
reckon its related to this: http://www.youtube.com/watch?v=8mbA606ZRWI&eurl=

probably not :D (that was 22nd of Sep btw)


Definitely not related ;) I'm not in Mexico, and my images were taken on the 23rd. Also, whatever it is in the video on youtube, it is NOT a meteor! Its probably another fake like the other "meteor videos" there. The light which is saturated keeps vanishing, thats not going to happen with a large meteor. You can see a large dark object there when it stops glowing, if that was real and hit Earth we would all know about it by now. Large fireballs travel at 11-40km/second, so if it was a real meteor it would have to be a LONG way away to be moving at that angular velocity, and therefore the object would have to be many tens to hundreds of metres across to be resolved on that video. The americas would probably be experiencing the start of a cosmic winter by now!

Gordon

PostPosted: Thu Sep 28, 2006 3:56 pm
by Laurie
Gordon wrote:
Laurie wrote:Gordon, when was this picture taken?
reckon its related to this: http://www.youtube.com/watch?v=8mbA606ZRWI&eurl=

probably not :D (that was 22nd of Sep btw)


Definitely not related ;) I'm not in Mexico, and my images were taken on the 23rd. Also, whatever it is in the video on youtube, it is NOT a meteor! Its probably another fake like the other "meteor videos" there. The light which is saturated keeps vanishing, thats not going to happen with a large meteor. You can see a large dark object there when it stops glowing, if that was real and hit Earth we would all know about it by now. Large fireballs travel at 11-40km/second, so if it was a real meteor it would have to be a LONG way away to be moving at that angular velocity, and therefore the object would have to be many tens to hundreds of metres across to be resolved on that video. The americas would probably be experiencing the start of a cosmic winter by now!

Gordon


*runs*

just thought it was interesting, your post and that video. i smell conspiracy