I shot these last night, so I guess I just missed the "what did you shoot" ending June 13


I posted a pic of this same field last week, but that was a 2 minute exposure. Here is a 15 minute autoguided exposure.


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5DII + AP130GT (819mm f/6.3) 15 minutes, ISO 400


The technology we use these days for our hobbies is amazing.


For those not familiar with astrophotography, shots like this are done with the telescope on a mount that rotates as the stars move. This rotation is never perfect, however, so to take care of errors for long exposures one uses a second smaller telescope (called a guidescope) mounted on top of the main scope. A second ccd is attached to this smaller scope, and the ccd is connected to the mount and to a laptop computer. The computer watches the image of a star (called a guide star) through the guidescope, and whenever the star moves it instructs the mount to compensate. This process is called "autoguiding". In the old days, one had to look through the guidescope and compensate by hand if the guide star moved (and in the old days, I never dreamed of doing astrophotography [])