Posts Made By: john welch

Here's the astounding TAL 65!!

For those that aren't familiar. 65mm f/ 7.7 newt.

Performance farexceeds wild expectations.

If you find one grab it!


Thanks Greggo!
John

Say Mike,

I've wanted to ask if you have a thought(s) about some designer/manufacturer making an ultrawide zoom eyepiece. Say, 80*, 5-30mm f/l and 2.0" barrel size. Might have to be slightly variable in FOV.

I know it would be three things: Expensive. Optically challenging with inevitable trade offs. Mechanically challenging with some trade offs as well.

The idea would be a general purpose eyepiece that would relieve us from playing that tiresome 'eyepiece checkers' game all night long. I would love to see single f/l eyepieces become semi-obsolete. Surely we would still need a couple of exquisite planetary eyepieces, maybe others.

If it's possible, it probably isn't something a manufacturer would like to do for fear of sales losses in the single f/l designs. However, I'd give up a thousand or more if say Al Nagler offered one.

Yes there are three or four good 1.250" zooms offered today and I've owned each of them. I use 'em for grab and go but the field of view suffers just enough that I have to grab my 350 lb. eyepiece case and think about loading and unloading the focuser some 10,000 times before dawn when going to a dark site.

Maybe it's a bit early in optical evolution, but when someone does spend some capitol to produce one, Their name will live on as a revolutionary dude. 8O

Mike and anyone with a thought.......

Thanks,
John

Here's an old question. Just hopin' for new answers. 8)

I have an older 9mm Nag that needs an eye cup, plus a few other various ones needing the same).

Any thoughts?

Thanks,
John

Howdy,

I finally "finished" my backyard "Little Red Caboose". (That's what my wife calls it). :S It's 11'x 11' inside.
'Still using my '92 10" LX200 (w/upgrades)in the backyard.

Thanks,
John

Hi Jim,

I received Richard Handy's plans for the 'Quick Dome'.
I haven't built a structure yet. The materials used
are very lightweight and probably easy to construct.
The entire structure would rotste on castors on a
wooden or concrete slab.
I'll probably opt for a top rotating dome with plywood
as the primary material. The info is invaluable for
helping one think "out of the box" for this type of
structure.
I called Richard before ordering the info. He is very
friendly and informative. Neat guy!

ScopinUSA
John Welch

Hey Paul,

The polarizing filter is good for several things, not
just the moon. It is necessary to look at the moon at
several image scales to study topographical features
that are small and large scale. 'Resolution' of fine
altitude and shape features require no filter, the eye
will adjust for brightness level. 'Albedo' features can
be hidden in glare without discreet filtering you can
achieve with a variable polarizer.
Transitions of surface albedo is sometimes the only
way to determine morphology.

Thanks, John

Hi Floyd,

Yep we have clears skies in AZ but the thermals
are awful!
John

I use this eyepiece in a 10" LX200 and several Pierre Schwaar newts, 10" to 17.5". The eyepiece works very well in all of them. It's pretty darn close to my 31 Nag. It's more than worth twice the price. There's actually some real pride owning this one!. I bought it from Anacortes.

John

James,

I've spent many, many nights with two friends, one with the 18" and one with the 20". The 20" out performs the 18" hands down in resolution and brightness. the 18" is slightly undercorrected, the 20" star tests perfectly as far as an eye can discern on a star diffraction test.

I have a 17.5" Pierre Schwaar f/4.8 that tests 'perfectly' and, except for less brightness than the 20", it outperforms the 18". It also has a silvered mirror that seems to be stable here in Az., and seems as bright as the 18". (The extra .3 f/l is a good thing).
I worked on a new 18" Obsession a few months ago that was very good. I used mainly Naglers with it and found the paracor helped slightly but wasn't absolutely necessary. Maybe a panoptic would have needed it but I didn't use one at the time.
I guess I would always recommend the 20" for the extra aperture and the focal length if you don't mind the extra cost. Bulk and weight are so similar that I wouldn't consider it a factor.

Thanks,
John

Thanks,
John

Congrats Inge!! If the world is clouded for 180 days, we'll know who to blame!

John