CaliBall Special Offer

Directly from Optiper.com

It is now possible to buy both versions of the CaliBall right here on this website. 

CaliBall, a calibration artifact and mount for use in the Random Ball Test.

Interferometric optical test precision is primarily limited by the interferometer transmission sphere quality. The CaliBall is a means of in-house transmission sphere calibration using the Random Ball Test. The CaliBall is designed so that it can be used immediately before or after a critical test of an optic without changing anything in the test setup other than inserting or removing the CaliBall itself.

Transmission spheres are factory calibrated, but shipping, handling, thermal and other environmental effects degrade the factory calibration precision. The CaliBall eliminates these uncertainties by calibrating the transmission sphere in the test set up, an assurance that the interferometric test results are precise.


The CaliBall uses averaging of random patches of the CaliBall to calibrate transmission spheres exactly the same way surface roughness interferometers are calibrated by averaging random patches of a plane surface. The calibration procedure is simple and the precision of the results are easily calculated.


Two CaliBall Models

Two CaliBall Models

The CaliBall comes in two models: CaliBall I for either horizontal or vertical interferometer set ups or CaliBall II for horizontal interferometer set ups held in a Zygo type 4” bayonet mount that provides the adjustments to align the CaliBall II to the transmission sphere.

Limited Time Special Offer

Limited Time Special Offer

For the first time ever both CaliBall models are available directly from Optical Perspectives Group.

You can purchase either CaliBall I or CaliBall II and receive $100 Discount by using special coupon code CALIBALL2017.


Case Studies & Testimonials

Why is proper alignment so important?

Here is a case of a very happy customer due to better optics.

A few days ago an astronomer friend of mine commented that he had gotten the optics of his telescope improved and the improvement reduced the time it took to get data by a factor of 3. For an astronomer this is a dramatic improvement since observing time on large telescopes can cost thousands of dollars an hour.

My friend did not say how the optics had been improved, but the important point is that better optics, whether due to figure errors, mounting or alignment mean more productive optics. I generally think of better optics as a better product leaving the manufacturing facility without thinking about how much the better optics mean to the productivity of the customer.