The 3" Wynne coma-corrector is capable to cover the 36 × 36 mm sensor of the
G4 camera with pinpoint star images. Also vignetting is acceptable if
slower than f/4 primary (and appropriately big secondary) Newtonian
mirror is used. Unfortunately the mechanical design of the corrector
provided by ASA brings some challenges when the corrector has to be
attached to the camera and possibly the OAG. The corrector tube has to
be attached using six M3 screws from the camera side. A question how
is it possible to screw in some screws from the side of camera when a
camera must be there naturally arises.
The 3" Wynne corrector also requires back focal distance between 58
and 59 mm. It is necessary to stack a
sensor in the insulated CCD cold chamber, mechanical shutter, filter
wheel for reasonably thick filters and OAG into this space and also
provide necessary room for screws holding the corrector.
The 3" ASA Wynne coma corrector adapter on the G4 camera
body
So we designed ASA 3" Wynne adapter for G4 cameras consisting of
two parts. One part replaces the M68 × 1
threaded ring on the OAG (the Wynne adapter itself does not use the
M68 thread). The other part is attached to the Wynne coma corrector
using six M3 screws. The another set of six M3 screws is used to hold
these two parts together.
The 3" ASA Wynne coma corrector adapter on the G4 camera
body
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