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Samir Kharusi | all galleries >> Galleries >> Magellan, NSW, Australia > Antares
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6-7 Aug 2005 Samir Kharusi


Near Goulburn, NSW, Australia

Same 200mm/2.8L lens at f2.8, 59 x 1 minute exposures at ISO 800. This illustrates one of the nuisances of going piggy-back. Slewed to a second target, balance got compromised; could no longer track for 3 minutes. Had to cut down exposures to one-minute each, and even then the yield dropped to only 65%. When shooting wide-field I prefer to remove any large OTA and mount just the camera and its lens on the mount. Amazing how much the tracking improves when a mount designed for 20kg has to carry only 3kg. Since this is the most colorful region of the entire night sky, perhaps it's worth clicking "original" to see a larger version, so you may swim around in it. Don't worry, I am not giving you a multi-megabyte version, just enough to fill your screen. Aaah. That H-alpha gives oodles of colour! On a previous trip to Oz I had shot the same target with an unmodded Canon 1Ds and it was very difficult to get the colours to show up with anywhere near this depth and saturation. That attempt, with almost the same integration time, but rather weak colours, can be seen on the next slide. OK, don't get confused. The next slide is upside-down compared to this one, taken with a 100mm lens (only half the focal length used above) and on a 1.6x larger format. The image above has North towards the right. With this orientation it sort of gives an ethereal impression of an elephant's foot, complete with toe nails :-)

Modded Canon 20D + UV/IR Blocker,Canon EF 200mm f/2.8L II USM

other sizes: small medium large original auto
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Guest 16-Jul-2009 12:13
Thank you.