Craters Humboldt and Hecataeus

Sketching: For this sketch I used: white sketching paper 12”x 9”, HB, 4B, 6B graphite pencils, a blending stump and a plastic eraser the sky was darkened using black Conte' pencil. After scanning, Brightness was decreased (-2) and contrast increased (+2) using Microsoft Office Picture Manager. Telescope: 10 inch f/ 5.7 Dobsonian and 6 mm eyepiece 241x Date: 11-3-2009, 4:45 - 6:00 UT Temperature: 7° C (45° F) clear, calm, low humidity Seeing: Antoniadi III Colongitude 99.1° Lunation 16 days Illumination 99.8 % Frank McCabe