"Alan French" wrote in message
...
"Mark De Smet" wrote in message
...

I've put togather a widefield refractor (62mm F4.5), but I am having
trouble verifying it's collimation.

Specifically, I can adjust the objective by several degrees, and cannot
see any difference in the performance. I have tried both a 26mm and 4mm
eyepiece (11 and 70 power respectively), I cannot tell the difference
between way off, and close collimation.

Mark,

Use a Cheshire, and everything should be fine. Take it outside on a nice,
sunny day. Put the lens cover on and insert the Cheshire directly into
the
focuser and rotate is so the reflective portion is pointed toward the blue
sky. Look through the Cheshire and adjust the lens until all the
reflections you see are concentric. No need to worry further.

Clear skies, Alan


And please, please, please do not point it at the sun on this sunny day!
even for a moment! Hard boiled eyes are not attractive, and there is the
chance that the heat will melt cements, or other parts of the telescope.

Harvey