Focus Problems

[peter.h]

I have C9.25 with Atik One "6.0 Mono CCD, Atik GP, CW and OAG"

So... SCT -> GSO Crayford -> Atik One. Problem is I can get both CCD's to focus but not together...I'm really confused when/if I should be using the mirror to focus or Crayford and the order:confused2:.

Peter

[multiweb]

First focus your imaging camera using the primary focuser or the Crayford. When you're in focus adjust the spacing on your OAG to reach focus with your guider. You might need some spacers.

[peter.h]

Thanks...yep I ran out of adjustment on the OAG. Thanks sometimes I know the answer i just start thinking maybe I missed something..I'll buy some T thread spacers. Also if I use just the crayford to focus, is there a postion I should leave the mirror in...like fullout or in etc.

Cheers peter

[multiweb]

Just check with the manufacturer what the normal back focus distance should be. Adjust the primary mirror ball park to give you focus on the main camera with your Crayford maybe half way out so you've got enough travel in and out.

[peter.h]

Thanks :)

[jsmoraes]

We can say that the distance between the prism (or mirror) of OAG and sensor of main camera must be equal to the distance between the prims (or mirror) of OAG and sensor of secondary camera.

A fine adjustment can be done by the adjustment ressource of the OAG.

Focal length is focal length, for both cameras. Maybe you will need some spacers to secondary camera to make them equal.

The prism or mirror of OAG may be positionned out of the field of sensor of main camera. It will take information of the periphery of total field. If the prism or mirror of OAG is postionned in front of sensor you will see a less bright area on the final photo due to obstruction of partial or total light information by prims or mirror.

There will be a great offset between what main camera will see and what the secondary camera will see. For example: with my set of instrument if I am shotting beta Crux the secondary camera will be seeing the Jewel Box Cluster.

[peter.h]

Thanks Jorge and Marc...I.ll get some spacers and try again..