August 17, 2012

Catching Meteors - January Quadrantids

     Back in January, the Quadrantids were predicted to be a pretty good shower, given the lack of moonlight and the amount of comet dust we were likely passing through.  Hence, I decided to give it a whirl with my DSLR (Canon Rebel XS) with the stock 18-55mm lens at 18mm.  Here's the logic I used to get something.
     Highest ISO possible, with largest aperture possible.  Why?  Since meteors are objects that only appear for less than a quarter of a second, I need to maximize its exposure compared to the exposure of the rest of the picture, while still getting a good enough picture of a constellation.  If I had lower ISO or smaller aperture, it would require a longer exposure time which would mean the meteor would be visible for a shorter fraction of the exposure, making it dimmer.  After taking some test shots with ISO 1600 and f/4, I found that a 20s exposure gave me the best constellation shot without too much light pollution.
     So with the settings ready and two charged batteries waiting, I set my remote shutter to continue taking 20s shots until the battery died or the memory card was full.  I did have to switch batteries part way through, which you'll notice in the video.
     I only got about 1.5 hours worth of the shower, but I was able to take all of the pictures and load them into iMovie and shrink the display time of each to 0.1s to create a movie.  Really the only purpose of an iMovie in this case is to use it to try to find the meteors in the pictures.  Playing it allows me to watch many at one time and it's easier to see them when they flash up on the screen.  It also helps to have 20 sets of eyes in the classroom checking it out, too.  We found two other "meteors", though I'm not quite convinced.
    Using the timing in the video, I was able to find one....yes, just ONE meteor.   Oh well, I DID get a picture of a meteor!  Alas, here's the original photo.
     After cropping it and doing some darkening in Photoshop (I'll post on that stuff later), I got the final picture, which I'll probably frame.

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     This was all done by trial and error, although I did do a little bit of research to get some general ideas.  The problem was that most of the stuff online has ISO settings of 3200 or 6400, which my camera does not have.  Have you captured any meteors?  What settings did you use?

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