Found this in my cabinet of old astro paraphernalia, most of which is 20 years old or more and long forgotten. University Optics 55 mm Plossl, anyone remember these? First clear night will drop it in my 102 mm ED to see how it performs.
University 55 mm
Posted 03 July 2020 - 10:23 PM
I was about to say I thought I had an Orion version of this, but it is a 50mm rebrand of a Parks Optical Plossl. It has nearly the same barrel as yours. Similar white font (I do not think it is quite the same), green font for "multi-coated".
I cannot find an image on Google images for my exact model, but it is [visibly] remarkably similar to yours.
You can definitely tell someone was copying someone else's design. :-)
Posted 03 July 2020 - 10:29 PM
They were likely made for University and Parks by the same manufacturer. In Japan.
- eblanken likes this
Posted 03 July 2020 - 11:00 PM
I have a very old one, and love it! That said, I evaluated it and found that they cheated on the coatings. Only the top surface is coated, which they did on all their eyepieces back then... only the very top surface was multi-coated, the other (three) air-glass surfaces seem to have no coating on them at all! This was common, even rampant practice back then, many many decades ago. I was a coater operator at B&L, at the time, so was always scrutinizing coatings of other manufacturers... We did a lot of destructive testing of outside concoctions, and discovered that many/most companies were cutting corners, it they thought they could get away with it. University was right in there. Note that the "multi-coated" logo is, technically accurate. What they don't say is Fully Multi-Coated. Tom
- SteveG, SteveV, MarkGregory and 1 other like this
Posted 05 July 2020 - 03:31 PM
According to the description, UO did indeed get it correct as your top lens most likely has multi-layer coating which corresponds to #3.
1) Coated: at least one optical surface has a single layer coating
2) Fully coated: all surfaces have a single layer coatings
3) Multi-coated: at least one surface has a multi-layer coating
4) Fully multi-coated: all surfaces have multi-layer coatings
Fully multi-coated would have come later I suspect.
Posted 05 July 2020 - 04:04 PM
I suspect there is more than a coating issue with my UO 55 mm. it rattles when I rotate it back and forth.
Edited by dhkaiser, 05 July 2020 - 04:04 PM.