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Just found out my telescope's focuser was off by 0.0001 inches... wait, really?
I was reading a forum thread about collimation errors and someone mentioned that even a tiny shift in the focuser drawtube can mess up star shapes. Out of curiosity, I put a digital caliper on my 8" dob's focuser last night and measured the travel at different points. The darn thing was off by 0.0001 inches on one side, which I thought was nothing, but I guess that's enough to cause those slight oval stars I kept seeing on bright nights. I've been blaming my eyepieces for 6 months. Has anyone else checked their focuser with a caliper and found something that tiny actually mattered?
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jade31mo ago
That 0.0001 inches thing got me. I did the same check on mine after a frustrating night of weird star shapes, and sure enough, tiny bit of slop in the drawtube. It's wild how a measurement that small can mess with things so much. My eyepieces took the blame for months too. So yeah, your caliper is probably telling the truth, trust it.
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