Oag with a 900mm refractor.

[Mumia]

Hello everyone,

I am currently in the process of building my astrophotography setup and would appreciate your advice. My main scope is a LZOS 152/1200 refractor, which I will be using with a Riccardi 0.75x reducer/flattener, giving me an effective focal length of 900mm.

For my imaging camera, I plan to use the Player One Poseidon-C, which is equivalent to the ZWO 2600MC. For guiding, I’m considering the Player One FHD-OAG MAX with a 14x8mm prism.

I’m now at the point where I need to choose a suitable guide camera. I’m debating between the ZWO 174MM and the Player One Apollo-M. My main concern is ensuring that the guide camera will work well in this configuration.

Would it be more beneficial to stick with the OAG setup, or should I consider a traditional guide scope? If OAG is the better choice, are there other guide cameras that you would recommend for optimal performance with my setup?

Thank you in advance for your input.

Best regards,
Chris

[orly_andico]

I have a somewhat similar setup. AP 130/819 with a  cheap and cheerful Orion 3" flattener, EFL of 854mm. Using the ZWO large OAG with an ASI2600. My guide camera is an ASI290MM, which I picked because it had a similar pixel size as the ASI2600 and is compatible with the ZWO OAG.

Your issue will be if your guide camera of choice can reach focus with your OAG. I discovered that if the prism is extended too much on the ZWO OAG, the guide camera cannot reach focus.

That said - I have not had great difficulties finding a suitable guide star with the OAG, but I have had to increase guide exposures to between 2 and 4 seconds. All of my previous experience 10 years ago was with a separate guide scope. And to be fair, it was much, much easier to find guide stars that way. A guide scope of around 200mm FL should suffice to guide your LZOS 152/1200 accurately "enough." But frankly too much hassle for me now that I use the OAG.

I may change my tune when/if I cannot find guide stars and will have to dig out a guide scope...

Edited June 23 by orly_andico