Hello,

I’m using the TEZI to model surface irregularity. I’ve set the Zernike terms to be from 4-11, which excludes wavefront tilts. I see that terms 2,3 aren’t populated when I use the SAVE tolerance operand. The RMS wavefront error only matches my MIN/MAX value with tilt removed. I see the large tilt terms when I Zernike fit the toleranced wavefront. Why does the tilt term show up in this case?

Here is a simple file with one mirror surface. On axis only. 0.633nm wavelength. Aperture f/6, EPD

Here is the MAX tolerance file SAVE, without the 2,3 terms in the Zernike standard sag surface but tilts are significant in the wavefront.

The RMS to centroid is 2.08 waves which is close to the 1 wave RMS error input to TEZI in double pass (due to mirror). Why is the RMS to chief so much different? 

I’m probably missing something fundamental…

Thank you,

John