Will an Orion SS Autoguider be ok with my cpc925 & oag?

[evilgeenius]

Hi

I'm looking for a suitable Autoguider for my CPC925 & off axis guider and was wondering if the Orion SSAG would be ok?

Reading around it seems as though a much better option would be a Lodestar Autoguider, but the £400 is more than I want to spend.

Are there any other decent autoguiders I could use instead?

Cheers

Chris

[ollypenrice]

You don't bombard the chip with light in an OAG so a sensitive camera is a good idea, as is one with a good chip size. There were a couple of Atik 16ic cameras on the For Sale boards and I have been using a pair myself for several years. They're brilliant. Another favourite is the QHY5, I think. I haven't used one but lots of people do. I also have a Lodestar and like it a lot. Guiding, especially at your kind of FL, has to be right and is worth a bit of investment.

Olly

[Cornelius Varley]

According to Bern @ ModernAstronomy the QHY5 and the Orion SSAG are the same camera.

Peter

[evilgeenius]

Yeah i've read that too Peter.

Will it be sensitive enough though?

Sent from my HTC Desire using Tapatalk

[Merlin66]

Yes,

For 90% of the spectroscopic work I do with the C9.25 and the C11 (I use a beamsplitter instead of the OAG) the QHY5 works well.

I also use the ATiK16ic on one of the spectroscopes, but will be changing to the Lodestar in the future (ease of fitment and focus)

HTH

[evilgeenius]

Merlin, if the beam splitter splits the beam 50-50 then it should be easier to guide on compared to my OAG where only a small portion of the light is seen. So It seems like I still can't be sure that the QHY5 will be good enough.

[Merlin66]

No, my beamsplitter is a 4% reflective and 92% transmission to the spectroscope.

The big difference obviously is that I can aquire my target star, position it on-axis (for the spectroscope slit) and then guide on the star....indefinately!

EDIT: I should say the size of the pick-off prism has nothing to do with the brightness of the guide star..it's just like guiding on a star image from a diagonal - no real light loss. The only impact, obviously, is the amount of the FOV you can work with.