Do you belive in good or bad luck ‘omens’? If so, here’s one for you. This is a photograph of Venus transiting our sun. The transit event occurs in pairs a little more than a century apart. The last time it happened in our lifetimes was 2004, just before the Tsunami in Indonesia. It won’t happen again for something like 105 1/2 years from now.
So why am I posting this image? For one, I think it’s kind of interesting when things like this happen. But the real reason was because it took a lot of effort to learn how to take a picture of the sun with a digital SLR. There are a few excellent resources (below) that will help you if you want to take a picture in the future.
The Story of the transit in ancient times
I thought it would be interesting to share the story of the early astronomers who tried to witness this event. Some of them are quite tragic… The first person ever to record the phenomenon was a young astronomer called Jeremiah Horrocks in Much Hoole, a tiny village in the north of England. In November 1639, he watched it using a small telescope.
Horrocks died of unknown causes two years later aged only 22, and it was up to Edmond Halley (yeah, that guy ‘Halley’ of Halley Commet fame) to add to his legacy. In 1716, Halley called on nations to join forces and record the event from different positions around the world.
He realized that timing the transit from different spots would give astronomers comparative figures to calculate the distance between the Earth and the Sun using trigonometry. This was the first time accurate data could be obtained for the event.
My favorite story happened a centurylater in 1761. French astronomer Guillaume Le Gentil went to India in answer to Halley’s call, but missed it because of a stormy voyage. He waited in India for eight years for the next one in 1769, but missed that, too, because of clouds. To add insult to injury, when he returned home Le Gentil found out that he had been declared "dead" by his wife who actually remarried and spent all of his money with her new husband… nice!
Whether you are of a superstitious or a scientific mind, do not look at the sun with the naked eye.
Either use special solar viewing glasses (make sure they come with a CE safety mark) or use a telescope to safely project the image on to a screen.
Good thread on "welding glass" as a ND Filter
I shot this with a Canon 100-400L plus 2x teleconverter and a 7d. It was all mounted on a Vanguard Tripod.
Quick point of scale… Venus is 23.7million miles away (at its closest point) and the Sun is about 150 million miles away. Venus is 0.9488 the size of Earth. These two figures give you an idea of how massive the sun is co(and how far away everything must be).
I mounted the gear on a tripod and used gaffer’s tape to attach a #14 shade welder’s glass to the lens hood. If you do this – make sure you use the right welding glass. You also need to make sure absolutely no light can get in behind the welding glass. It will create relfections and distoritons.
By w4nd3rl0st (InspiredinDesMoines) on 2012-04-01 17:17:29