Posts Made By: Frank Bov

Mike,
As the owner of all five ... good choices!

Given the 24mm Konig is my least favorite, I could see replacing that with the 25mm MK-70, which I'd love to try! The 22-24mm Pan are good options, as are the 20-22mm Naglers (I have the 22mm as a NEAF blem and it's definitely found the home the 22mm Pan never quite moved into.) and the 22mm Vixun superwide. However, all are $$$ by comparison.

OTOH, the 16mm is my most favorite and I'll be long dead before that one goes. Very little can beat it for any one of AFOV, on-axis image sharpness, contrast, and most importantly, transmission. An 18mm Ortho would feel tight by comparison, with no improvment in the view. A 15mm Pan has dimmer images, even if they're sharper at the edge. It's in my f/10 more than anything.

That's not to say I wouldn't (didn't?) get the other Orthos.

HAve fun,
Frank

How is simple - they just put a 2" flange around and above the 1.25" barrel.

Why is fascinating. These Ultrawides start with an aggressive negative lens - like a Barlow - as the field lens. This causes the optical path to expand, and so require a much larger second element group to catch all the light. They then use strongly curved, multi-element eye lenses to pull all that light into your eye while maintaining an extraemely wide apparent FOV.

Since the eyepeice body is so wide, they figure it's more convenient for users to have the 1.25/2" capability built in. Plus, you'll find the 2" position requires more out-focus because it sits deeper in the drawtube. In Newtonians, you want the eyepeice as close to the secondary as possible and this lets you get closer.

HAve fun,
Frank