Celestron 2" Mirror Diagonal- is it letting your system down?

[pyrasanth]

Some of you probably know from some of my previous posts that I purchased a Hotec Advanced Laser Collimator. No matter how hard I tried I could not get a successful collimation but the result I got with the Hotec was always consistent but out of collimation with the mirror image badly skewed to one side even though the collimator showed successful alignment. I emailed David from Hotec the chairman & explained the problem. He immediately suggested that I collimate from a straight path & not use the diagonal. As I did not have an adapter that could couple to the back of the telescope I ordered a moonlite dual CS focuser & discarded the diagonal. Previously with the diagonal in place the collimator showed that the primary optical axis was not in line with the eyepiece & having no way to adjust the Hotec collimator would never be successful. The collimator uses absolute mechanical collimation where a real star test uses relative collimation. So I collimated using the moonlight focuser and a straight through path & the collimation proceeded beautifully with lovely concentric rings.

This proves that the Celestron mirror diagonal I have is not very good & indeed is a detriment to an otherwise fine system. I am disappointed that Celestron can produce such a fine telescope then let themselves down by using either a second rate mirror diagonal or fail on the quality control as I have a bad example. I will now be forced to upgrade although in the absence currently of an alternative I will have to carry on using this. The moonlite CS is a fantastic focuser & I would highly recommend it- no more rotating the Celestron diagonal locking ring that jams solid. It will improve the telescope experience no end.

I'm going to order a click lock Baader Dielectric star diagonal  when the funds allow!