Jump to content


8" f/9 Spherical mirror Sold!

Price - $105.00

Ad Number: 107714

Posted: 08 Jun 2017

Please sign in to message advertiser

Originally made by me as a super planetary flex mirror project. I had made an excellent flex scope at 8" f/7. Exceptional. No time for this one.

I labored to get this to a smooth accurate sphere, see the 150 lpi Ronchi pic. I "star tested" it on the bench with a laser diode and got perfect diffraction pattern at 600X.

As a sphere it is 1/4.7 wavefront in a scope. According to Adler's FLEX program, the flex accuracy for this mirror would be theoretically 1/258 wavefront. Flex tension is calculated to be 3.73psi, so it's an easy one to flex. Wedge allowance is .023" and this one is .005", so it's ready.

Would make a super Chiefspeigler.

Flat ground back, tapered Pyrex blank. Has shallow chips on back edge...no big deal. Coating has a couple blemishes and a couple of insignificant scratches in the glass from my shop. Ignore the water droplets in the photo.

I used it once to test a 16" flat via Ritchey-Commons test.

Reduced to $105. Buyer pays shipping, please.


  • Condition Very Good
  • Location Maine

Advertiser Info

Powered by Classifieds

Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics