Re: [ATM] RC design

[Richard <cnc@cncservo.co.uk>]

Hi Jonathan,

It ray traces OK and is diffraction limited over your small
field with a few very minor alterations. Beware of that primary
to secondary distance as it looks to be critical. You've also
got quite a poor image plane curvature.

Surf     Radius      Thickness      Glass    Diameter    Conic
OBJ      Infinity       Infinity                    0
1        Infinity            820                  110
STO      -2032          -800.686    MIRROR      406.4   -1.03724
3        -584.408       818.2548    MIRROR        107   -3.37777
IMA      -217.9131                            26.9565


That curvature and some of the astigmatism could be corrected
with a two lens corrector. I'll have a go at working it out if
you're interested. That would give you a bigger FOV - your
current field will fill your CMOS sensor OK but won't fill a
1.25" eyepiece. Your secondary mirror is OK for a bigger field
but I've not ray traced a diagonal so I'm not sure about that.
 
-- 

Best regards,
 Richard



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