Quote:
|
Originally Posted by asimov
I prefer to think of collimation as simple if one simplifies his thinking: I "square" my mirrors up to suit the focuser...not the other way round. I added a mod to my primary mirror holder to take it "off-axis" if I chose to do so, or the necessity arose. Call it collimation in reverse if you want. lol. Imagine if the focuser was NON-MOVABLE....what do you do to "square" it to the mirrors? You "square" the mirrors to the focuser, yes?
I prefer the "caveman" days.   |
It's not that simple if the focuser is way out ,unless you've a very oversized tube.
The lightpath will be obstructed by the tube if the main mirror is not parallell(or close to it) to the tube. That will cause vignetting of the view.
Nothings immovable.
I'm only following advice from more knowledgeable people than myself on this subject.
Nils Olaf Carlson,the author of the link Mike posted, even suggests making masks for the end of the tube to suit the mirrors to test the relationship of the entire components of the OTA. A lot of trouble for something some deem unnecessary.
Each to their own but a properly setup newt gives better views than one thats not.