Rini 2" 28.5mm Eyepiece

I purchased one of these last week and received it in time for Saturday
night observing in the Sierra foothills. It's $35+$7 shipping, from
Paul Rini.

This s a 2" eyepiece with 6 elements, single coatings on the lenses.
The eyepiece casing and barrel are nicely machined black metal, with
one screw head visible on the outside of the casing. The apparent field
of view is around 75=B0, maybe a touch more. Eye relief is 12mm, and was
comfortable for use without glasses. In my 22" f/4 the view was crisp
to about 60% of the radius, and the image was reasonably bright and
contrasty. On deep sky, views were very pleasing, with M81 and M82 (for
exampole)fitting into the field with room to spare. OTOH, chromatic
aberration (Jupiter, for example) is very noticeable when the object is
not centered.

This eyepiece failed to reach focus in a friend's 10" f/5 (I think it's
an f/5) - not enough infocus.

In another friend's 18" f/4.5, views were very contrasty, but the
double cluster showed the effects of coma and astigmatism near the
edge.

The effective field stop is about 42mm, and I estimate that the
eyepiece weighs less than but close to a pound.

I'd say this is an excellent eyepiece to use for public viewing, and a
decent eyepiece if you can't afford $80 for Anacortes' version of the
BW Optik 30mm.

Paul has some of these left, and says it performs very well with a
barlow (it did work well with my 2X Powermate, crisp views to 85% of
the radius). I also tried it with a Visual Paracorr, which seemed to
have less effect than expected.

Clear skies,
Shneor Sherman

Thanks for posting that.
Very lots of useful info.
Greatly appriciated.
"shneor" wrote in message
ups.com...
I purchased one of these last week and received it in time for Saturday
night observing in the Sierra foothills. It's $35+$7 shipping, from
Paul Rini.

This s a 2" eyepiece with 6 elements, single coatings on the lenses.
The eyepiece casing and barrel are nicely machined black metal, with
one screw head visible on the outside of the casing. The apparent field
of view is around 75°, maybe a touch more. Eye relief is 12mm, and was
comfortable for use without glasses. In my 22" f/4 the view was crisp
to about 60% of the radius, and the image was reasonably bright and
contrasty. On deep sky, views were very pleasing, with M81 and M82 (for
exampole)fitting into the field with room to spare. OTOH, chromatic
aberration (Jupiter, for example) is very noticeable when the object is
not centered.

This eyepiece failed to reach focus in a friend's 10" f/5 (I think it's
an f/5) - not enough infocus.

In another friend's 18" f/4.5, views were very contrasty, but the
double cluster showed the effects of coma and astigmatism near the
edge.

The effective field stop is about 42mm, and I estimate that the
eyepiece weighs less than but close to a pound.

I'd say this is an excellent eyepiece to use for public viewing, and a
decent eyepiece if you can't afford $80 for Anacortes' version of the
BW Optik 30mm.

Paul has some of these left, and says it performs very well with a
barlow (it did work well with my 2X Powermate, crisp views to 85% of
the radius). I also tried it with a Visual Paracorr, which seemed to
have less effect than expected.

Clear skies,
Shneor Sherman