And yet another thread that shows an instrument but stops without describing the views
The views are quite nice once everything is calibrated which is not a simple task. All the work is done by the tracking mirror and it has to keep the sun in a very narrow field. As I remember it, ours was equipped with an H-alpha rear etalon and front ERF made by Del Woods. I think it was tuned somewhere between 0.9 and 1.5Å and it showed wonderful views of prominences along the limb. We also used it for white light views of sunspots. They later got a Calcium K-line filter but it mainly just showed a very dim purple orb visually. The proms were what knocked everybody’s sox off tho! H-alpha was relatively scarce back then unless you were a bigger institution or had really deep pockets. The beauty of these these things is that the tube is stationary. The last time I saw it mush have been around 1990.
Edited by Terra Nova, 12 February 2020 - 10:29 AM.