A Coal Sack Among the Jewels
Just acquired an Epson printer/scanner from an op shop, and was delighted to find it has film scanning capability. Quality’s not quite as good as a dedicated unit, but pretty good all the same. So, I’ve been going back through some old negs and slides, and here’s one of the first through.
The Coal Sack is a dark dust cloud near the Southern Cross. It obscures the light of the Milky Way beyond it, giving rise to the appearance of a hole in the mass of background stars. Called the Coal Sack by early European astronomers, it is also known as the head of the Emu according to Aboriginal sky lore.
This image is a time exposure (approximately 10 minutes), and shows the stars trailing across the film as they apparently revolve around the South Celestial Pole – although it is actually the Earth’s rotation on its axis that gives the appearance of the stars’ movement. It is easy to see in this image that the stars are a variety of colours, from bluish to yellowish; the bluer the star, the hotter it is. Also visible are a few pink areas in the Milky Way, where new stars may be forming in the glowing nebulae of hydrogen gas.
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Image Copyright Duncan Waldron © 2008
This image may not be reproduced without permission
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A Coal Sack Among the Jewels belongs to the following groups:
*Amazing Orton Effect* - Limit 3/day , Astronomy and Timelapse/Long Exposure Photography Available for sale asGreeting Cards, Matted Prints, Laminated Prints, Mounted Prints, Canvas Prints, Framed Prints and Posters

redcow
this is cool but i feel dizzy !
Duncan Waldron replied
I prescribe browsing the rest of my portfolio, and buying a calming image ;-)
redcow
I might just try that : )
drec
nice one
Matsumoto
Any idea what the amperture was?
Duncan Waldron replied
I generally close down 1-2 stops from max aperture, so probably f2 or 2.8. I’ve enhanced this slightly with various bits of processing – the Milky Way wasn’t so evident in the original:

Nikki Trexel
beautiful..i like that it is pure unadulterated startrail – no pesty foreground or clouds or moon to distract. :)
Duncan Waldron replied
Thanks for that Nikki (I was an astronomer before I became a photographer, so I don’t even think of these as photos without foregrounds, and if you want stars, you don’t want the Moon & clouds!). Sometimes I do use a foreground though :)
OldBirch
Love the explanation.
You were an astronomer! Wow! In high school, that was my dream…until I found out there was one job opening per year…
Duncan Waldron replied
I was an amateur photographer, which led me to want to photograph the things I was seeing through the ‘scope; after that, I worked as a photographer at an observatory – the best of both worlds :) It was great fortune that a job came up just as I was finishing my phot’ course.