[ATM] Schmidt Camera Quandries

["dezrteagle" <dezrteagle@cox.net>]

Well, new to the list, but not to pushing glass. However I've embarked on a trip into new territory: building my own (and first) Schmidt camera. I've just finished an 8" f/2.2 primary for the camera, but have run across some kinks in the rest of my plans. First, does ANYBODY know of a vendor who WILL supply a small quatity of Invar 36 (for the skeleton) and won't hang up on me when they find out I'm not NASA? My local metal haunts here in Phoenix are: don't have it, can't order it, forget it! I've tried going the way of a substitute (i.e. epoxy-graphite), same results. Second, paging through my copy of Telescope Optics (thank you Rutten&Venrooij), the idea of flattening the field with a Plano-Convex lens really caught my attention. My interest stems from the amount of time that might be saved following this path, from what I've been able to gather, the process of machining the film holders is very time consuming (correct me if I'm wrong). Has anybody tried this? I have a metal lathe and end mill, niether of which is CNC capable. If footing the cost of half a dozen lens and a few hours at the old lathe and drill press can give me a faster result, so be it! Many Thanks, counting on any help! 
Thanx-Jim
_______________________________________________
ATM mailing list http://www.atmlist.net/