Oag
I'd recommend the Astrodon MMOAG for its thin profile, load capacity and reliable connections. I use one of these with my RC and a large camera load. If backfocus is not an issue the lesser MOAG is a good option. As is the Van Slyke Engineering OAG - which has excellent adjustability for its pick off mirror. All of these are quite expensive and may require special adapters to fit securely and reach focus with the guide camera. None of these are cheap items however.
Being able to place the prism so that it doesn't pick off aberrated stars needs to be considered as well.
guy
|