Ken,
these photos show the setup I finalised last night. All professionally held together with packing tape, old plywood + a cardboard box to put over the top
. I need to confirm fibre size.
I sacrificed an old slr camera body to use as the collimator holder as it was far more sturdy than anything I would make. The exit point of the fibre is on the plane where the film use to run, making it at the focal point of any lens I wanted to use as a collimator. The angle of the grating film, (Edmund Optics NT54-509) and the 350D fine tuned through trial and error. I was using a halogen desk lamp as a test light and the first order spectrum covers the full width of the frame, so 4000 - 7000 ang covered approx 3400 px giving very roughly 1 A/px. The 1"1/4 adapter goes into the telescope eyepiece and collects part of the light cone.
It's probably only good for extended objects, but I'll be trying it on the sun this weekend.
One thing I did do was to put a "donut" shaped piece of high temperature ceramic paper in the adapter to handle the excess light from the sun, and avoid melting the plastic.
Cheers
Mark
