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Mar 20 2015

…when the sun is eclipsed by the moon

Friday 20th March 2015 saw a solar eclipse visible over the British Isles, subject to the vagaries of the British weather. I have some form in taking pictures of the sun through my telescope. With solar eclipses taking place in the UK only once every 10 or so years (the last one was in 1999), I thought it worth the effort to take some pictures.

The key piece of equipment was the Baader AstroSolar filter mount I made a while back. It’s designed to fit on my telescope but works pretty well for naked-eye viewing and with my Canon 600D camera. I used a Canon 70-300m lens, mainly at the maximum zoom with varying exposure parameters depending on cloud. I used autofocus in the main but manually set exposure time, aperture and ISO. Consumer cameras aren’t designed to give good auto exposure for usual activities such as eclipse observations.

Here’s a closeup of the filter:

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The uninitiated may not be impressed by the finish on this piece of equipment but as a scientist of 20 years standing I’m happy to report that I’ve had plenty of stuff in my lab in similar style – it’s good enough to do the job.

Solar eclipses last a surprisingly long time, this one was a little over two hours with first contact of the moon on the suns disk at 8:26am in Chester. This photo was taken at 8:26am, you can just see the moon clipping the edge of the sun top right.

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By 9:01am things were well under way. The birds had started their evening song around this time and it was starting to feel unusually dark for the time of day.

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The maximum of the eclipse was at 09:30am, by this time clouds had appeared and I used them as an ad hoc solar filter.

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By 09:50am we were well past the maximum:

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The last photo I managed was at 10:18 before the sun disappeared behind the clouds:

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Finally, this is a collage of the majority of pictures I took – some of them are pretty rough:

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