Quote:
Originally Posted by Cluster
The GSO laser is so easy to use for both the secondary and primary that honestly I don't know why anyone would use something else.
Anyway, that's my experience :-)
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Because a cheshire is more accurate and a barlowed laser (google this) is even better. A straight laser relies on the laser spot hitting the centre spot of the mirror
exactly. If you are 2 mm off, then your error at the eyepiece is 4mm--
way too much for an f5 Newt. See the very informative article
here originally published in Sky and Telescope, which also describes the barlowed laser. For mine, the BL is the easiest and most accurate way too go, but a Cheshire comes pretty close (I use the Orion and find it's OK).
Geoff