Quote:
Originally Posted by 5ash
I have tried collimating my telescope , a fast 8" Newtonian with a Cheshire eyepiece and find it fairly easy and accurate. However I find the cross hair at the end of the cheshires tube difficult to focus on and to obscure my view of the mirrors centre spot. This could be overcome to some extent if the crosshairs had a circular centre that you could look through.
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Hello Philip,
The cross-hairs of a typical sight-tube is meant to align the focuser axis with the primary mirror. That is why the secondary mirror is adjusted to align the cross-hairs with the primary center. In your case, the cross-hairs marked on the back of the eyepiece do not serve the same purpose.
Jason