Yep, got a Ronchi screen or two. If you are referring to testing for astigmatism, the Ronchi test is not good for that. Unless the mirror is really bad. There are testers for testing astigmatism, but the star test is even better. See another post from me about artificial stars. Mat -----Original Message----- From: utah-astronomy-bounces@mailman.xmission.com [mailto:utah-astronomy-bounces@mailman.xmission.com] On Behalf Of Chuck Hards Sent: Monday, October 17, 2011 8:05 PM To: Utah Astronomy Subject: Re: [Utah-astronomy] ATM session report and next planned date No Ronchi grid, Mat? Or artificial star? You can determine a lot from a mirror in daytime with either. The star test is the acid test, but a Ronchi will get you 98% of the way there, with some experience. Too, an artificial star will let you test in broad daylight. _______________________________________________ Utah-Astronomy mailing list Utah-Astronomy@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Visit the Photo Gallery: http://www.slas.us/gallery2/main.php ---------------------------------------------------------------------------- This message and any included attachments are from Siemens Medical Solutions and are intended only for the addressee(s). The information contained herein may include trade secrets or privileged or otherwise confidential information. Unauthorized review, forwarding, printing, copying, distributing, or using such information is strictly prohibited and may be unlawful. If you received this message in error, or have reason to believe you are not authorized to receive it, please promptly delete this message and notify the sender by e-mail with a copy to Central.SecurityOffice@siemens.com Thank you