NGC 7789 open cluster in Cassiopeia. Taken Nov 2, 2010 with 105mm A&M apo refractor at f/5 with Borg .85x flattener/reducer and Canon 5DMkII at ISO 800 for stack of 5 x 10 minute exposures, Mean combined. Used Celestron CGEM mount and Celestron NexGuide on William Optics 66mm guidescope. All seemed to work well.
NGC 7789 area; taken August 15, 2007 from home. Stack of 3 x 4 minute exposures at ISO800 with Canon 20Da and 135mm L-lens at f/2.8. Field equals 7° bino field. Rho Cassiopeiae in field above NGC 7789
This is a complex of faint nebulas and star clusters in Cepheus: While this exposure shows the field as one large nebula, the arc-shaped region at top is catalogued as NGC 7822. The region below with dark lanes through it is Cederblad 214. The loose open cluster at right is NGC 7762, with the small yellowish cluster (dimmed by interstellar dust) is King 11. A small, sparse cluster at the centre of Ced214 is Berkeley 59. The field of view is about 8° by 5.5° with the 250mm focal length RedCat astrograph. This is a stack of 8 x 8-minute exposures through the William Optics RedCat 51mm f/4.9 astrographic refractor with the red-sensitive Canon EOS Ra camera at ISO 800, and blended with a stack of 8 x 15-minute exposures through the Optolong L-Enhance narrowband filter, with the EOS Ra at ISO 3200, to make up for the nearly 3 stops loss of light from the filter. But it really pops out all the faint nebulosity. All images stacked, aligned and blended with Photoshop. Guiding was with the Lacerta MGEN 3 stand-alone autoguider, which also controlled the camera shutter and applied dithering of 10 pixels between each frame to reduce thermal noise without having to apply LENR in camera or dark frames. This was on the Astro-Physics Mach1 mount.
