I have an Orion 90mm Mak with a simple 1/4" tripod thread on the bottom. I have a Vixen-compatible mount to which I am trying to attach the scope. I picked up a SkyWatcher Star Adventurer Ball Head Adapter, and unfortunately the threaded post is 3/8" (as is, it turns out, the bottom of the Vixen-based mount).
First question: is 3/8" a standard in the astronomy world, or is it a standard with the Vixen and Vixen-compatible mounts?
Second question: is there an easy way to attach a Vixen rail to a scope with a 1/4" thread? I have looked at a few rails from various vendors and can't seem to find something that I can say will work with 100% confidence.
Sorry for the newbie questions.