OAG and Dithering

[Starwiz]

Any advice on what settings I need to change for dithering now I've gone over to using an OAG?  It doesn't seem to be working at the moment.

I was previously using an Orion Mini Guide scope (FL=162mm) and ASI120.

I'm still using the ASI120 for the guide camera and the scope is a SW200P on NEQ6 mount.

I'm using PHD2 and APT.

Thanks

John

[Laurin Dave]

I think you need to increase the Dither scale in PHD2 by the ratio of the focal length of the SW200p to 162 mm ie about 6 to get the same actual dither movement in your imaging camera..  

 

[Starwiz]

2 hours ago, Laurin Dave said:

I think you need to increase the Dither scale in PHD2 by the ratio of the focal length of the SW200p to 162 mm ie about 6 to get the same actual dither movement in your imaging camera..  

 

Thanks.

[Starwiz]

For the record, I also had to change the Dithering Stability because the star was moving around too much at the higher magnification which caused the dithering to time-out.

I upped it from 0.7 to 1.7 and it seems to be working OK now.

John

[Laurin Dave]

the other thing that might help is to increase the "Search Region" in the PHD2 Advanced Setup Guiding Tab

[Starwiz]

35 minutes ago, Laurin Dave said:

the other thing that might help is to increase the "Search Region" in the PHD2 Advanced Setup Guiding Tab

Thanks, I'll try that before my next imaging session.