[Raytrace] Dall Null for 22" f4.5

[Robbin Palmer]

I set up a Dall Null test in OSLO Lt per John's instructions and found
0.15 wave error in the wavefront using an f = 300 mm, d = 66 mm plano
convex lens. Then I tilted the mirror 1.7 degrees as it would be in a
real setup to avoid interference of the lens with the light reflected
from the mirror and bring the focus over to the knife edge, reoptimized
and refocused. The wavefront error jumped to 20 waves! Did the same
thing for 0.5 degree, error of 1.8 waves.  Looks to me like I can't use
this test.  Am I doing something wrong?