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Got a thin skin? Then look elsewhere. Post a link to an image that you've made, and invite others to offer their critiques. Honesty is encouraged, but please be positive in your constructive criticism. Flaming and just plain nastiness will not be tolerated. Please note that this is not an area for you to showcase your images, nor is this a place for you to show-off where you have been. This is an area for you to post images so that you may share with us a technique that you have mastered, or are trying to master. Typically, no more than about four images should be posted in any one post or thread, and the maximum size of any side of any image should not exceed 950 px.
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 by Gordon on Wed Sep 27, 2006 6:46 pm
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. 
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 
Gordon D70, D200, CP5700
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Gordon
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by thelastname on Wed Sep 27, 2006 7:25 pm
Interesting and well done Gordon.
Movie works fine.
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by Yi-P on Wed Sep 27, 2006 9:06 pm
Very interesting thing you can do with this.
Did you use a tracer/tracker device for the shots? Specially the 10mins exposure ones.
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by Gordon on Wed Sep 27, 2006 9:18 pm
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 D70, D200, CP5700
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by wally on Thu Sep 28, 2006 12:29 am
We get some truly amazing stars down here in Adelaide!!
Where am I
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by Gordon on Thu Sep 28, 2006 2:59 pm
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
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by Laurie on Thu Sep 28, 2006 3:56 pm
Gordon wrote: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
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(that was 22nd of Sep 
