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Hi Ken, sorry to disagree, but the Howie Glatter collimation works just the same as a Cheshire. Difference is the Cheshire has the 45 degree cutout to view from the focuser end whereas the HG has a white plate on its front face, and you view the reflections through the front of the scope. In any case I tried my Cheshire in case I was missing something but it gives the same result.
I’ve not had confirmation from any source that the rear element of the TOA assembly is fixed in the OTA. I’ve been working on the assumption that it is, and that the two sets of adjusting screws work only on the front two elements.
But looking closely at the assembly today, it appeared as though all three elements were moving with one set of screws. I can’t fathom how you can individually adjust three elements with only two sets of screws. I’d be grateful if someone could enlighten me on that.
After another day of fiddling about moving one set of adjusting screws through ther range of motion, I think I have found a sweeter spot than I’ve seen before. Airy Discs balanced on either side of focus. But, the point of focus is a little vague, and my laser reflection is back where it was at my last two attempts, and not in the centre where is expect.
I’ll try it on some real stars a little later tonight.
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