We had another clear night - cold at 3 above so I put the 9.25 inch ACHRO to work with a modded Canon 6D at ISO 1600 and a Baader Contrast Booster filter for this image. There were 7 shots of 8 minutes each at f/12 (106.5 inches ) I guided manually as usual for me using a guide scope at high power with the standard double cross hair reticle. The whole scope system is hand built from the lens grinding to the mount which really tracks nicely using some Vexta stepper motors and a joystick for corrections. The objective is a BK7 crown with an F2 flint Clark style air spaced glass.
The moon is waning so the sky was fairly dark and no sign of northern lights. I could have gone 10 minutes easily but since I let the camera do dark frame subtraction 8 minutes was used to save some time. By the time I was done shooting the temperature was at -3 F.
This is full frame.