Peter Drew
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Blog Comments posted by Peter Drew
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13 minutes ago, Merlin66 said:
Why the x2 Barlow???
I use the ASI 174MM but need a tilter (1.6 degree) to suppress the Newton Rings.
The original configuration was for the inclusion of a binoviewer which required a Barlow to reach focus. The surprising side effect of this was the increased field of view of the eyepiece in conjunction with the 5mm blocking filter as well as better performance. (The "how and why" of this is currently a subject of debate). As a binoviewer is not being used at present, an extension piece takes the place of it.
Ha Solar Imaging and Observing Rig
in Astro Projects
A blog by Gina in General
Posted
The correct focus position was set up using an optimally tuned PST less its 40mm objective. The subsequent mod is a stage2 so the black box is empty. The digonal containing the blocking filter fits in an aperture machined in the rear face of the black box. Spacers have been supplied that make up any difference in the post etalon focus. Any very small adjustments for different eyepieces are by way of the OTA fucuser and lie within the etalon position tolerances.