I made the sketch at the Okanagan Observatory on July 9 2011.
I used pastels on black paper along with a brush and smudging stump. The stars are a mixture of white charcoal and a white gel pen.
The sketch was done with a 15″ dob using a 20mm Nagler as well as a Lumicon UHC filter.
The SQM-L was 21.24