Quote:
Originally Posted by programmer
Just to clarify.. the star collimation test you did is the one to check collimation, not the optics (i.e. the 'airy disc') test?
But, I guess you'd know if your collimation was out or not. As I said, I'm just curious.
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Hi Programmer,
Yes I focused in and out of focus on a bright star (or any star for that matter) and no, before you ask, it wasnt a binary or double star. Coming from far out of focus (focuser high in the tube) the image was a round donut with the four vanes visible which got smaller and smaller until I got closer to the focus point. At focus, or as close as I could see to it, the star appeared streaky or comet like with a "tail" off to the right and appeared like a piece of bird poo. Once I focused too far in, the star's image started to look like a thin smoke ring that kept getting bigger and bigger around the central part of where the star actually was. The problem is that smoke ring looks like it is dented on the right hand half as if it was being affected by a breeze and being pulled to the right as the focus goes further in the tube.
Additionally when focused, (only just remembered) the star or planet looks like the 3 colour pixels on an OLD colour TV where the red, blue and green images are slightly offset from each other, like when you move the individual colour channels around in Registax. It doesnt change with EP changes so I would assume this is a collimation issue with the streaky images and offset colours?
A final note, the scope was MUCH better than this before I collimated it. It may all come back to bite me on the ass.
Chris
