Previously with my Astrotech 8″ RC telescope, I found it very simple to adjust the collimation – and it helps that it held its collimation so well that this was not required very often. But then came the upgrade bug and I bought the Orion VX12 12″ Newtonian to grab more light for imaging. With that came the problem of collimating a Newtonian, which is something I’ve never done before and have absolutely no experience. And because mine is a fast Newtonian at F4, it is crucial that I get the collimation right each time – and this needs checking everytime I move the telescope. I did own a Cheshire eyepiece collimator, but wanted to get a laser collimator to help with this. Hence after researching online and considering the cost, I chose to get the Baader LaserColli III.
Cost: £69.00 from Amazon Prime. This is about in the mid range for laser collimators, with cheaper ones in the £30 mark and the Howie Glatter collimators from £95+. As I have Prime membership, I could get the LaserColli III next day – I ordered on Saturday and it arrived on Sunday – Great!
The Baader LaserColli III comes with the laser fully aligned in the factory to be fully collimated, and should not need adjustment of the laser itself. But the key to success with using it, is to follow the instructions fully.
The laser is turned on via a knob which turns about 30 degrees. At the other end of the laser collimator is the 1.25″ adapter to fit into the eyepiece holder. There is a white dot there which acts as a point of reference for aligning the laser in the eyepiece holder.
With the laser switched on, you can see a tiny red dot lighting up in the housing. As there is a hole in the reference plane of the LaserColli, you should see that the laser passes straight through it if the laser is still collimated correctly – if not, then it needs to be returned to the seller as it is no good.
The ideal placement of the LaserColli is for the focuser to be pointed up vertically. The LaserColli should sit in the eyepiece holder as such:
i) focuser with only one locking screw, the white dot aligns to point at the locking screw,
ii) focuser with more than one locking screw, align the white dot centered between two locking screws.
In my case, the focuser has 3 locking screws, and so I align the white dot to be exactly between two of the locking screws. Not setting it up ideally can lead to more problems with collimation rather than get it right, which is why I follow the above setup.
Once the LaserColli is placed correctly, you will then check to see if the laser bounces off the secondary mirror to hit the center of the primary mirror (there is a black donut in the center of my primary mirror). To center the laser, fine adjustments are made to the screws of the secondary mirror first.
After adjustments, the laser should look like this and be centered on the black donut.
Once the laser is centered on the primary mirror, then it is time to adjust the primary mirror screws to center the laser back onto the LaserColli reference plane. Below the red dot of the laser has bounced off the secondary mirror, to the primary mirror, and then back to the secondary mirror and then onto the LaserColli reference plane (i.e. the translucent material with lots of crosses on it). As you can see below, the laser is slightly off center, so some correction of the primary is needed.
Once the adjustment is done, it should look like the picture below, with the edge of the hole in the center of the reference plane just about lighting up red. What I tend to do after this is check the alignment all round the focuser at 120 degrees from the original alignment point, just to check that it is truly aligned properly. I then recheck that the laser is still centered on the primary mirror black donut. Once these checks are done and I am happy with the collimation, I will tighten the locking screws of the primary mirror with an allen key. Final confirmation is with the Cheshire eyepiece collimator. And then it is done.
I have to say that the Baader LaserColli III when used as recommended, works extremely well. In fact it has saved me on more than one occasion when I messed up the collimation completely with the Cheshire eyepiece due to getting the steps wrong; the LaserColli allowed me to get the alignment back to where it should be very quickly and accurately. So now I only use the Cheshire collimator to confirm that I have got the collimation correct.
The Baader LaserColli III is not cheap, but works well when you follow the instructions and mount it the ideal way. I would not be without it, as I have learnt how to use it correctly, and it has served me very well. But as I have only had it for a few weeks, it is too early to sayt how well it will hold up to the strain of regular usage. But as its construction looks solid and well made, my impression is that it should hold up well. So I would highly recommend this.