Yes, David, I agree...the 30 mm WS Type III acts similar, but not
as pronounced as my 2" 32 mm Erfle...but the curvature effects
are not nearly as pronounced...very good analogy. I noted that too.
Clear Skies,
Tom W.



David Knisely wrote:
Hi there. You posted:

Curious if you denoted any difference with issue of blackout. It
seems to me from memory the Widescan was more prone to it than is the
new Chinese clone. This potentially having a lot to do with the
smaller, useable field stop acting as an eye guide. Did you by chance
get an indication one way or another?


The exit pupil edge is fairly sharp and pronounced so you do need to
keep your eye fairly well centered when using the eyepiece, but the it
wasn't showing some of the horrid blackout or kidney beaning I have seen
with some eyepieces. The eyepiece overall acts a bit like an Erfle, and
the unit has a somewhat conical hard plastic eyecup at the end to act as
the "guide". Clear skies to you.