127mm Mak's are virtually made for BV's IMO.
127mm Sky-Watcher SkyMax/AZ5 bundle with WO bino's.
Believe it or not, I decided to try my binoviewer in my ETX-90 OTA, mounted on a Celestron Alt-Az (with slo-mo). The common saying with 90mm Maks is that they run out of light before they run out of detail.
So you would say such a scope with a binoviewer which splits the light in half would just not work. Add to that, the target, Jupiter was maybe 15o off the horizon and the conditions were typical NJ summer; hazy, hot and humid.
But I gave it a go anyway. To make things even harder, I used 16mm eyepieces with a 2x nosepiece/Barlow, giving 155x.
Well. The disk of Jove was a fairly good size in the binos. The edge was sharp, and it was not at all lacking for light! It wasn’t blindingly bright, but much brighter than I’d ever expect.
“Okay, joe1950, we’ll buy that fish story. But for sure with the planet so low in the NJ weeds with the soupy summer haze, and using a small older Mak with a largish secondary obstruction, you’re not going to expect us to believe you actually had any contrast to see any hint of the belts?”
The contrast between the very dark belts and the lighter areas was the most surprising thing of all! I was floored at how the NEB and SEB stood out, with edge variations visible. The poles had a slightly different cast from the rest of the disk, and I could just make out a hint of the whitish sub-belt that has been part of and to the south of the SEB; it runs directly into the GRS that was (confirmed by my Jupiter app) on the far side.
Last year I recall using this ETX-90 on Jupiter and being disappointed at how dim it appeared.
But this observation with the binoviewer was a complete 180! I personally question what some observers report that seems impossible or improbable. So I’m not into exaggeration or wishful seeing. I report what I definitely see and nothing more. And that’s what I observed.
Next clear night I’ll duplicate conditions and verify, if I get the same results.