Celestron 82291 instruction manual Step-by-step procedure to collimate your Newtonian telescope

On Left: Clear, translucent Reference plane with etched cross-marks

Most laser collimating devices use a sim- ple opaque piece of plate glass to act as indicator for the returning laser beam.

Many small suppliers just scratch the glass by using sand paper in order to get a cheap opaque reference plane.

Our Clear Reference plane is etched (not printed!) with hundreds of tiny crossmarks so that the returning beam lights up in the ever so tiny grooves of each individual cross that is being touched by the laser light.

Not only does this produce a much more concentrated dot, the main benefit is the fact that our reference plane is not opaque!

Whenever your optical system is just slightly misaligned, it is no problem to im- mediately recognize the reflected laser beam on the glass reference plate.

But what happens when you don’t see any reflected dot at the reference plate due to a moderate de-collimation of your optics?

In the case of an opaque reference plate the returned laser beam will not be visible at all and you will be unable to view the returned beam in the focus tube.

The clear reference plane of the Laser-Colli™will allow viewing down the focuser tube through the etched plate, and in most cases it will be possible to glimpse a reddish glow were the laser beam grazes the focusing tube internally.

That is the reason for placing theLaserglass-Collireference™plate as near as possible towards the focuser

and to design the body of thein a way that makes it easy to look almost straight into the focus tube from behind.

Step-by-step procedure to collimate your Newtonian telescope

1. Mark the geometrical center of your primary mirror.– Remember the important requirement that the laser beam touches the primary mirror centrally

exactly in the middle of your center mark.° angle against the ocular holder, If the secondary mirror is tilted only slightly out of its necessary 45

the laser beam will not be reflected down towards the center of the main mirror.

Therefore you should prepare your system for the first (and all following) collimation(s) by marking the geometrical center of the main mirror.

This requires, in Newtonian telescopes with a closed tube, removing the main mirror cell from the

tubeLaser. The-removalColli™results in the need for re-collimation afterwards of course, but this is done with

thein no time.

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