The Dutch Observatory

September 6, 2008 on 7:07 pm | In Planets | Comments Off

Wednesday the clouds from Gustav started clearing and the sky was clear and stable as it had not been in a while.  This was an opportunity to test my new barlow lens.  A 2x Williams Optics.  Used in the binos.  It screws right in the filter thread of the DMK.  Used with the CPC925 and the DMK21AU04.AS in this way it gives an effective focal ratio of F13.  I ran 7 sets that night, one of them with the Celestron 2x Shorty Plus cell used in a similar way.  The latter one gave a 2x maginifcation, but the focus for this barlow seems to be very critical.  Just as the test images from last month show.

Here the two best sets from this night.