telescope stuff

Cleaning the Optics in a Schmidt-Cassegrain
This guide details the process of safely cleaning the optics of a Schmidt-Cassegrain telescope (SCT), focusing on the meniscus corrector, primary mirror, and secondary mirror.
The author emphasizes that while many amateurs fear handling the corrector plate, it is manageable with care. The document outlines the required tools (isopropyl alcohol, distilled water, Pec Pads, hex keys, etc.), steps for dismounting the corrector with registration marks, cleaning methods using a soap solution and analcohol-based cleaner, and reassembly precautions.

How do I collimate my Schmidt-Cassegrain
This paper explains the process of collimating an SCT, demystifying common fears surrounding it. It stresses the importance of collimation for sharp planetary and lunar views and argues that factory screws are more precise than aftermarket thumbscrews.
Using only a screwdriver or hex key, the procedure involves defocusing a bright star at high magnification, centering the secondary shadow, and adjusting the three secondary screws incrementally. The author advises patience, re-centering the star after each adjustment, and warns against leaving screws loose. A final refinement step looks for Poisson’s Spot to achieve perfect collimation.
