Mar 132012

Tonight was a rare clear night and I decided to photograph the conjunction of Jupiter and Venus.  The actual conjunction occurs on March 15, 2012, when these two planets have the same right ascension.  However, in true Southern Ontario form, it will likely be a cloudy night March 15.  Throughout the month of March, they will appear close together in the Western horizon.

As it turns out, getting a shot was not so easy to do on a whim.  My first attempt using an Orion EON f/7.5 120mm APO refractor with a 900mm focal length failed.  There was too much magnification to show both planets.  So, I quickly swapped out the Orion for a Meade 80mm f/6 APO refractor with a shorter focal length of 480mm.  However, that did not work as well as the planets were still too far apart to fit in the frame.  So, I grabbed an  f/6.3 focal reducer which is normally used for a Schmidt-Cassegrain  telescope and jerry rigged it with some spare hardware to make it work with the Meade 80mm.  It was not possible to get exact focus, furthermore, there would be some astigmatism.  Nonetheless, it was good enough to take some shots.

I also tried to take some shots with a DSLR on a tripod using a telephoto zoom, but they did not turn out so well.  Setting the correct exposure is another problem.  If you expose for Venus, then you lose Jupiter and its moons.  If you try to expose for Jupiter’s surface, you lose its moons and Venus will be a huge overexposed white blob.  I’m sure with multiple exposures and layering, one could make a much better shot.

The image below was taken using the Meade 80mm APO refractor, a Celestron f/6.3 focal reducer and a Pentax K-5 DSLR.

You can see Jupiter’s largest moons: Ganymede, Callisto, Io and Europa.

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