[avandonk]

Jase I have a GstarEX behind a Canon cmount F1.8 16 to 160 mm zoom. I have a mark on the zoom when it exactly shows the same field as the Canon 5DH amd 300mm F2.8L. I have a LPR filter over the GstarEX's sensor so light pollution is no problem. I can see the Helix Neb in real time when integrating 128x and at f2.8 in 7" LCD monitor mounted on the zoom lens. The same goes for the Flame and HH nebs. I use Registar to do a final check before an imaging run to the data already collected.

I can rotate the Canon lens and camera as it has a lockable rotating mount. The fridge limits this rotation so I do not bother.

The twelve panel mosaic of the Vela SNR was done this way.

The whole lot is guided by 90mm Mak 1150 FL and GstarEX camera. Can't find a guide star? Just up the integration! It is important to slow the autoguide correction interval to match the hysteresis of integrations above about 32X.

You will also notice the lens has Kendrick dew heaters wrapped around it. These are thermostatically controlled so the lens retains perfect focus all night everynight as the lens temperature is always at 20C. I have not needed to refocus for three months as I leave the heaters on 24/7 which also stops any chance of condensation on cold wet nights. The PID ( black box at rear of Peltier fridge) controls the Peltiers and the fridge's temperature is held at plus or minus 0.1 C to the set temperature. This means darks match lights exactly for noise subtraction.


Bert