Z-Factor (Lens Centerability)

Written by Dan S.

When a lens is placed between two bell chucks during the centering operation the lens may center on the radii in contact with the bell chucks. This equation tries to quantify how well the lens will 'self-center'. This is interesting from an optomechanical engineering standpoint because is similar to how many lenses are mount into housings.

The 'Z-Factor' , as it is sometimes called, essentially determines the tangent of the angle between the surface normal of each radius at the contact height and compares it to a certain value. The 0.56 is that tangent. So essentially if the angle between the surface normal of the two surfaces  at the contact height is >=29 degrees than the lens should self-center. If the angle is smaller then the lens will not self-center with at least a little help.

One of the attachments below is the beta release of an Android app (.apk file) along with the Eclipse Project Project, that calculates this Z-Factor. At some point (once it is no longer a beta release) this will be placed in the Android marketplace but until then the installation needs to be done manually using the .apk file. If you have never installed an APK file on your phone, here is some instructions. Ignore the section talking about adobe air. Thanks Flashbuilding YouTube Channel! 

Since this is my first Android app, and I am not a programmer, I'd appreciate any comments, corrections, or suggestions (email them to dstrosch at gmail dot com).


Karow, H.,H. Fabrication Methods for Precision Optics, Wiley, 1993, pg 524

Scott Sparrold,
Jul 15, 2011, 3:32 PM
Scott Sparrold,
Jul 18, 2011, 12:41 PM
Scott Sparrold,
Jul 18, 2011, 12:42 PM