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Old 26-06-2005, 07:25 PM
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[1ponders] (Paul)
Retired, damn no pension

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Join Date: Nov 2004
Location: Obi Obi, Qld
Posts: 18,778
Lucky bugger John. Glad you got clear skies to see it. Its great to see everyone getting into the spirit of the occasion.

There is another opportunity on the 4/7/05 for another conjunction/occulation when Venus and Mercury pass through M44 ,The Beehive cluster. I'd love to see what you guys with Digital non-SLR cameras can do with this one.

If you're not sure how long you can expose for before getting star trails. A rough guide is time = 700/FL of camera lens (you might have to check the manual that came with your camera for this) eg. with a 50mm lens then the approx exposure time is 14 sec, but a 28 mm lens ups the exposure time to 25 sec. Good luck for those you give it a go.

The full formula is t(sec)=1000/(F*cosDec) where dec is the object Declination. Ignore the - sign for southern decs. Important to remember, if you use say a 50 mm lens and image something at 30 deg Dec you will include objects in the field of view with lower Dec angles (close to the celestial equator 0 deg dec). So work out the field of view of your lens, find out the lowest Dec angle included in your image and use its t (sec) for the shot to reduce the likelihood of trails.

Last edited by [1ponders]; 26-06-2005 at 07:52 PM.
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