Managed to get three panels before cloud intterrupted play.
Panel Details
Canon 5DH, Canon 300mm F2.8 at f/3.5. Astronomik 13nm HA filter.
Exposures 20x240s at 1600 ISO, fridge at -10.0C.
Medium image 6MB. FOV 12x8 degrees.
http://d1355990.i49.quadrahosting.co.../velmos_4p.jpg
I will just keep going and get more panels in HA and O3 and colour to make a full colour mosaic of as large an area as possible.
Bert