double pass autocollimator for null testing paraboloids

This is a video of our new doublepass autocollimation tester for null-testing parabolic mirrors. It has a superbright blue laser, as you can easily see. It has an elliptical flat mirror that has been trepanned by us. It was acquired from Surplus Shed and looks like military surplus; was clearly a flat diagonal mirror for god-knows-what, with a minor axis of about 8 or 9 inches, don't remember exactly. The mirror under test is a fair one that is still being worked on. It has a bit of a turned edge and a raised center.

Category:

Science & Technology

Tags:

• null test
• amateur telescope making
• foucault test
• ronchi test
• autocollimation
• flat mirror
• parabolic mirror
• paraboloid

[foreilly1958]

Guy,

Nice double pass autocollimator!

The null test results are very accurate and I am certain that you will be continuing to produce high quality mirrors using this test.

Best regards,

Francis