Back focua OAG

ken_nneth

Hi, I am having problems with calculating the back focus for my OAG. I have an Celetron Edge HD8 with 0.7 focal reducer. Setup as follows:

Telescope

Reducer

Celestron 50mm extender

T2 entender 11mm

T2-T2 2mm

ZWO OAG 16.5mm

Filter 0.7mm

ZWO EFW7 20mm

ZWO ASI1600 6.5mm

The ASI1600 is in focus but I can not get my LoadStar 2 into focus and I am getting very confused with the back focus calculations. Could anyone please help with this.

Sam@ZWO

can you put one picture show how do you connect it?

ken_nneth

Thanks for response Sam, but the problem is now solved. The LodeStar chip was placed very deep in the housing so I added a spacer between the Filter Wheel and the OAG to increase distance. I also reduced spacers in front of the OAG and got good focus for both cameras.

Sam@ZWO

that's good news

usually the problem happens like this ;)