The chromacor color corrector that turns an achromat into an APO is one of the coolest developments in amateur instruments. However I find the collimation method of futzing around till you get it right cumbersome. I want a deterministic method of collimation on the star test just like collimating an objective, that is, three pairs of push-pull screws at the focuser so adjustments and tweaks can be done live.
1) The only focuser I know that has built in collimation for refractors is the Moonlight. Excellent focusers but screws are on the inside, so you must completely remove the focuser, tweak the collimation screws then replace.
2) Another idea I have involves a collimatable diagonal, but tricky to implement because the chromacorr must come after the mirror.
3) I finally found some inexpensive commerical parts that will allow for tip-tilt at the back of the focuser.
First here is a photo of the ScopeStuff adapter ring meant for use in replacing a Synta/Orion focuser with a GSO dual speed Crayford ($39.00 - #FNCI - Adapter Ring with Hardware for 2" Crayford Focuser); the silver ring is shown between the newtonian base and a standard GSO.
But instead, if you remove your 4" OD Synta/Orion/Celestron refractor focuser body, and install the ring using its three radial screws, you now have a foundation to install the Synta/Orion collimatable 2" Crayford focuser in the Second picture.
1) The only focuser I know that has built in collimation for refractors is the Moonlight. Excellent focusers but screws are on the inside, so you must completely remove the focuser, tweak the collimation screws then replace.
2) Another idea I have involves a collimatable diagonal, but tricky to implement because the chromacorr must come after the mirror.
3) I finally found some inexpensive commerical parts that will allow for tip-tilt at the back of the focuser.
First here is a photo of the ScopeStuff adapter ring meant for use in replacing a Synta/Orion focuser with a GSO dual speed Crayford ($39.00 - #FNCI - Adapter Ring with Hardware for 2" Crayford Focuser); the silver ring is shown between the newtonian base and a standard GSO.
But instead, if you remove your 4" OD Synta/Orion/Celestron refractor focuser body, and install the ring using its three radial screws, you now have a foundation to install the Synta/Orion collimatable 2" Crayford focuser in the Second picture.
Attached Image:
"--Granted, that's a worse case scenario. The destruction might in fact be ... limited to our own galaxy."
