kinetic
05-01-2009, 10:56 AM
Hi all,
Last night I tried my trusty homemade focal reducer
on the GSO-12 Newt for the first time.
This FR has served me well for years on my 8"F7 homemade
Newt with my series of modified webcams.
It is the 30mm objective from a riflescope and being a
beautiful little well made doublet, showed no noticeable coma
in any imaging with the F7 Newt.
On the GSO-12 is a different story however :)
Here are a few old favourites with the FReducer spaced about 40mm
from the DSI CCD.
Some vignetting on the HH shot pretty obvious after a severe
curves adjustment.
Coma seems to be off-axis type coma, so it could just have
been slightly misaligned in the nosepiece.
More experimenting to come....
regards,
Steve B.
Last night I tried my trusty homemade focal reducer
on the GSO-12 Newt for the first time.
This FR has served me well for years on my 8"F7 homemade
Newt with my series of modified webcams.
It is the 30mm objective from a riflescope and being a
beautiful little well made doublet, showed no noticeable coma
in any imaging with the F7 Newt.
On the GSO-12 is a different story however :)
Here are a few old favourites with the FReducer spaced about 40mm
from the DSI CCD.
Some vignetting on the HH shot pretty obvious after a severe
curves adjustment.
Coma seems to be off-axis type coma, so it could just have
been slightly misaligned in the nosepiece.
More experimenting to come....
regards,
Steve B.