I'm not experienced enough in OSLO yet to build a full model, to answer this for myself and won't be home for a few days so I can't use my stuff anyways.
So, just seeing if anyone can do a simple confirmation of the width of the light cone at any particular point, using similar triangles calc:
I'm modeling a common Celestron C6R, Synta lens, 150mm F8 with a 1200mm focal length. I'm looking for the point in the light cone where it will pass the light cone, without masking it, through the 2" entrance of a typical 2" focuser when wracked all the way in (max back focus).
So I'm using:
Width = Distance / Focal Length * Aperture
So, solving for 50mm light cone width, I'm coming up with it happening at 400mm from plane of focus. Does that sound approximately correct?
Application: shortening this OTA (and eventually re-building as truss) and finding where I can put the focuser (a typical 2" GSO crayford) to have maximum back focus without masking the light cone.