fivemack (fivemack) wrote,
fivemack
fivemack

It moves!

A squall-line came over this afternoon, down from the Orkneys on the wings of a tree-felling and ship-sinking wind, bringing behind it beautifully clear sky; Ed had said that he'd tried and failed to photograph the comet, so I wondered if it had faded substantially, and went out with a range of cameras.

With my little camera (Canon Powershot A510; 15s f/5.5, 140mm-equivalent, ISO 400) I get the left-hand picture. It's not a good picture - the lens is flaring badly around the brighter stars, and the colours are much too blue, with alpha Persei looking the actinic-blue of an O-type star when its spectral type is a more prosaic F5 - but it's a 200-gram pocket camera not intended for astronomy; the right-hand picture is with totally different kit but at about the same scale, taken by me on Saturday, to show that the comet is moving.



With a camera of inconvenient size (Nikon D100; 200mm, f/2.8, the camera and lens weighing in at 2.3kg, 4-second exposure at ISO 1000, push ISO up a couple of stops in gimp cursing at the lack of 16-bit-per-channel support) I get



So it's still pretty visible to me; I'm surprised that Ed couldn't get a picture of it without sky-fog issues (in that it's a lot brighter than sky-fog to me, and would be visible through it unless the exposure was so long that the sky-fog saturated), unless where he lives is a lot more floodlit than a central-Cambridge back garden.
Tags: astronomy, comet
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