A Full night of Stargazing

The rain has gone, the sky is clear and all looks set for a full night of stargazing. It is always a good sign when the skies clear after some substantial rain. It usually means the air has be cleaned of that interfering dust and gives best chance of dark skies. Tonight I will try my EOS filter which fits inside the Canon DSLR. The features of this filter are to reduce light pollution which comes from things like sodium street lighting, sky glow and moon glow. It does this by filtering frequencies associated with these pollution effects, most notably Sodium lighting (orange colour).

I've set the mount up and aligned on Polaris. I've then added the 6" Achromatic refractor. This is no small beast. I've performed an alignment on three stars and it comes back successful. So nest I swap the eyepiece with the DSLR camera. I have to connect two cables to a laptop to take photos. One is a USB cable that downloads the image. The second is a serial cable that is needed to trigger exposures greater than 30 seconds. Canon, like most DSLR manufacturers, provided the capability of exposures up to 30 seconds via the USB cable. Beyond that it requires a serial cable. I line up on a reasonably bright star and take a shot of a second or two and download to the laptop. After several more shots and adjusting the focus knob I am almost fully retracted getting it to focus.

First subject will be planet Jupiter since it should be a good subject for a refractor. After 40 minutes of shooting and adjusting timing the best I can get is an image of an over exposed Jupiter along with some of it's moon. Still it is worth it just for these. One can check with a monthly Astro periodical and it will tell you the position of the four inner moons for any given date in the month. So in theory I should be able to label each of these.

Second object will be the moon. For this I have to reduce the iris in front of the objective lens otherwise it will be much too bright. This also changes the focal ratio from F12 to F22 which is good for a lunar/planetary object. Quite a surprise it has given the image is nice and sharp but it is tinted blue! Now in hindsight that is to be expected as the filter is designed to remove light pollution as well a moon glow!

Just for interest one can use a graphics program to adjust the colour. Here I have altered it to appear more natural. Next up is a bunch of Open Clusters. All with varying interest.IC348: