Siebert Optics Multi Mag OCA

Started by Steve Stonehill, 03/02/2004 12:31AM
Posted 03/02/2004 12:31AM Opening Post
Hi Gang,

I purchased one of these from Harry and had a chance to test it this weekend. I was having trouble getting low powered views when Ha observing and this OCA solved the problem. Elements 1 and 4 placed in front of the blocking filter diagonal resulted in out-travel in my 80mm f5 and an approximately 2x view. The entire solar disk was easily seen in 25mm EPs and two huge prominences and many faint ones were visible Saturday. I also used it in my Vixen apos with two inch WO diagonals. I use Blacknight BVs so EPs above 24mm or so are somewhat vignetted but I didn't see any change in the field of view when this corrector was being used. I don't think the OCA was restricting the light cone at all. When viewing clusters like M35 and the Double Cluster the stars were pinpoints right out to the field stops in 20mm Plossls at every magnification. Jupiter, Luna, and Saturn all showed sharp contrast and detail as well. The only criticism that I think is worth mentioning is that it is a little awkward to have to assemble and disassemble the unit to change your magnifications. I plan on testing it in my SCT when I get some more decent weather.

Clear Skies,

Steve