Quote:
Originally Posted by bkm2304
Thanks for the info. One more question. Exactly HOW do I align it if it is out? And how do know when it is aligned? (Actually that's 2 questions isn't it!).
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Hi,
There are 3 socket head alignment grubscrews around the barrel (on my Bintel unit they are 1.5 mm hex) and you tweak these with an allen key. They are quite sensitive on mine.
I use a wooden jig (illustrated) and shine the laser on the garage door 5 m away. Rotate the laser in something like this, and if it is misaligned you will see the laser dot wander round in a circle.
Now if we say that the best practical visual alignment for the laser spot is within a 2mm circle over a 5m baseline (the laser dot itself is 1-2mm) this is a best alignment of + or - 0.0002 rad, or 41 arcsec. Over say a 1500 mm focal length this is a circle 0.6 mm in dia.
Now N.O. Carlin mentions that the diameter of the "sweet spot" around the focal point in a f/4.5 scope is about 2mm, and for best results aim for 1/2 that, so, with a base length of 5m we are in the ballpark.
GeoffW1