Re: ATM 310mm F/1.55 Schmidt camera update

[Dominic.Luc-Webb@molmed.ki.se]

> I did some adjustments to your Asphere
>These numbers yield a spot of .00127 mm. across the full
>3 degree field.
>AS1  -0.0000128240252
>AS2  5.2630071268e-10
>AS3  9.0609842047e-16

Thanks. My values (50% neutral zone) were:

AS1  -0.000016969464
AS2  5.220782e-10
AS3  8.870486e-16

May I ask where these come from and where you have 
placed the neutral zone? Your values are very close 
to mine, but apparently leading to some exceptional improvement, maybe. It has
already been suggested that 
I go back to an 86.6% neutral zone. My numbers for a 
neutral zone at 86.6% zone are even closer to your's. However, while this gave
excellent performace in green light (540 nm), essentially diffraction limited,
there 
was drammatic residual spherical abberation for 480 and 
630 nm light. My values at 50% zone, while not diffraction limited for all 3
colors, gave a spot of less than 10 microns for all wavelengths from 480-630
nm. I am 
therefore curious if you meant that the particular values 
you offer here give 0.00127mm spot for all wavelengths at 
the same focus or just applies to green light?

Dominic