Hello Charlie, I haven't been online lately, however, I was at TSP with Rick's 22 and my 16.5FX 3.6 and the 28" F3.7, and I completely agree with your details.
Thanks so much.Joseph ... All parabolic mirrors have coma as one of the optical abberations of the design. It is not a side effect of a poorly manufactured
Thanks.Joseph. ... If it increases at a declining rate as you move further from the center, that implies that it would be less noticeable at low power. -John
Thanks so much.Joseph. ... Dear Joseph, A paracorr is a "required" option. At 4.3f, coma is a given effect, but is easily corrected with a TeleVue paracorr.