On 6 June 2012, Venus passed directly between Earth and the Sun. This ‘transit’ won’t happen again until 2117, so I’m happy that I got some photos of it! I was asked to write a few words on my experience for the August 2012 issue of the AAO Observer newsletter, so in lieu of rehashing the same story, here’s what I wrote for the article.
I have to admit I completely forgot about the transit as I was booking flights to Cairns for a June holiday. As it happened, I would land in north Queensland the day before the event, and so with less than two weeks to go I frantically ordered some solar filter film online and checked the weather forecast. Cairns was given a fifty per cent chance of cloud cover, Sydney significantly less. It was pretty disappointing – having not seen the 2004 transit, I’d told myself months earlier that I would make a special effort to not only view but photograph the entire event and make a time lapse movie of it. Still, despite the short notice and iffy weather I thought I’d try my luck at hiring the gear I needed to do so. Incredibly I managed to find a suitable telephoto lens that wasn’t booked out, so I snapped it up and hoped for the best.
The beautiful tropical fishing town of Port Douglas had just been on the receiving end of torrential downpours when my better half and I arrived on the evening of June 5th. Perhaps it was our British blood that told us to ignore the rain, go to the beach, and – in the dark – find a suitable spot to set up early next morning in spite of it all. Well, thank heavens we did: Wednesday June 6th dawned without a cloud to be seen. From our little camp among (but not underneath) the coconut palms, I rigged up my camera and settled in for the next seven hours.
My setup was a Canon 50D digital SLR and a Canon 400 mm f/5.6 L lens with a 2x extender. This amounted to an 800 mm f/11 lens, which with the 50D’s sensor gave a field of view about three suns wide. The optical quality of this combination wasn’t brilliant, but it was cheap, small and most importantly it was available at the time. I’d made a solar filter for the front of the lens using Baader solar film and I also hired a gimbal tripod head to make tracking the sun (by hand!) a little easier. I used a timer remote to take a photo every 60 seconds, giving me over 400 frames to stitch into a time lapse movie. Not a single cloud got in the way that day – I was extremely lucky.
Something I really enjoyed, and that I didn’t expect, was talking to passers-by about what I was doing. A surprising number of people didn’t know about the transit at all, and almost all of the ones that did had left home that morning thinking they wouldn’t get to see it for themselves. It was terrific to give them that opportunity. Needless to say I left the beach that afternoon with a smile on my face.
UPDATE 2013-03-10: Here’s the time-lapse video!
UPDATE 2013-04-05: Here’s a post about aligning all the sun images with Python.