Important Notice: Our web hosting provider recently started charging us for additional visits, which was unexpected. In response, we're seeking donations. Depending on the situation, we may explore different monetization options for our Community and Expert Contributors. It's crucial to provide more returns for their expertise and offer more Expert Validated Answers or AI Validated Answers. Learn more about our hosting issue here.

Why do some observation tubes have notches cut into them?

April 26, 2017cut notches observation tubes

0

Posted

Why do some observation tubes have notches cut into them?

1 Answer

0

Posted

The notch guides placement of the locator pin on eyepieces that have a reticle. You focus such an eyepiece by rotating its diopter adjusted upper lens, while the locator pin keeps the reticle crosshairs or micrometer scale properly oriented.