I had a chance to try out these eyepieces, they are very sharp, and can see no reason
to relegate these to dust plug duty. There is a learning to using these, I think. I at first
thought I needed to pluck my eye lashes, but within a few minutes I think I've got the
hang of it.
I notice the field is bright, even the 4mm at 350 power.
I started thinking about the tiny elements in these eyepieces. I think this is a wise move
and probably done for less loss due to glass absorption. Also these designs have few
elements all adding up to a brighter image.
They are pleasingly sharp I'm surprised. I think the way they present the subject is not
nearly as nice as a modern eyepiece, but I think the sharpness is there.
I repaired the erecting prism case. Super Glue is perfect for Bakelite. And there's the 22mm
from the kit.
I can now travel back it time to 1970. The Sears 6345 90mm became available in the
catalog in 1970. I'm willing to bet all 400 of these scopes were built in 1969, serials are all
starting with a 9 for 1969.