Astro Photography

I haven't done a great deal of astro photography, largely due to a lack in focal length but as it was a relatively clear evening I decided to slap on the 100-400 and a 1.4x tele extender and see what I got. The tele extenders increase your focal length by either 1.4x or 2x, but you loose a stop of light with the 1.4 and 2 stops with the 2x, with this type of photo I wasn't too worried as I wanted to be at about f11 to start with. You also have to manually focus with the TX's, again shooting a moon this isn't too much of a problem. A tripod is essential as is either a cable release or using the cameras 10 second timer and I've just remembered mirror lock up, in this example I forgot about mirror lock up but if you have it under your custom functions use it as it reduces shake further. I started to appreciate that the moon is traveling at over 2000 mph and it soon moves from your viewfinder so you need to keep adjusting. When it comes to processing I found the histogram to be quite narrow so you need to stretch it a little either using levels in CS3 or the blacks and exposure sliders in Lightroom (or the tone curve) this results in more contrast. I also had to crop in quite a bit, this can be solved by attaching you camera to a telescope ;-) I took this around sunset so the sky was still quite blue but I converted to mono and dropped the blues right down. The info for this was f/11, ISO100, 560mm, 1/200sec.