I recently got a second-hand ES 127ED, the first gen. The first viewing was testing and looking at Jupiter and Saturn. I was able to focus to a sharp image. Both showed a defined white halo around the object, about 5x the diameter of them. It was almost as light as the planet was, making visual difficult. I can also see spikes from Jupiter's moons
At first I thought it was atmospheric conditions, but here in Salt Lake City it's dry and no clouds. I pulled out my WO GT71 and didn't get any halos while using the same diagonal and eyepieces. This eliminated light scattering due to high clouds, and over magnification of the eyepiece. I used both eyes and I don't have cataracts. (yet) It was cooled to ambient temps. It appears to be collimated, as when I defocus it I can see an even pattern in the circle. I'm sure I could test this more thoroughly but was looking for any possible reasons for the halo. All optics appear clean.
This topic was discussed then archived before but never satisfactorily answered. A halo with the 127ED but no halo with the GT 71 rules out atmosphere, eyepieces and diagonal, and eye problems. My wife experienced the same visual halo. When I move the planet to any position in the eyepiece it shows the same halo with no changes.
ES 82 degrees Series 18mm
Celestron Lumos 82 degrees 7mm
Meade Super Plossl 26mm LP
Edited by otterspace, 19 September 2022 - 12:37 PM.