Hi Bobby,
Quote:
Originally Posted by Bobbyoutback
Pleased to know you approve these , a question ?
The offset needed for perfect collimation can not be done with just a laser collimator can it !
Bobby  |
Offset collimation really only achieves one thing over and above centre/centre collimation and that is to make the 100% illuminated field perfectly circular. Without that offset is is slightly oval in shape. The difference is really pretty slight and I have never really seen the need to do it myself. "Centred" collimation provides just as perfect an image
in the eyepiece save for the non-circular 100% field. It is however more important if the telescope is used for imaging or photography. It is best achieved with a sight tube/Cheshire or an un-barlowed laser.
I recently bought a high-quality Tublug barlowed laser collimator myself, not because it does a vastly
better job, but it does make it quicker and simpler -- particularly when the focuser and the collimation knobs are about 3 metres apart and two or three steps up a ladder. Much more often than not I'm alone when setting up and observing with my telescope. The barlowed laser means I can stand/squat at the back and adjust the bolts and see the result in real time as I move the primary. I don't need to shuttle back and forth between the top end of the 'scope and the bottom as the adjustments are made and checked.
But I still keep my Rigel as a back-up, just in case the battery fails (it is a rechargeable).
Best,
L.