Cave Orthostar 16mm final gen model circa 1976

Here we have a solid-performing, 1976 Cave (Nikon or Kowa of Japan) Orthostar 16mm. As of right now, I don't have a top dust cap for it. I'm still looking though. And do know that I pack the geezers out of everything; so, you will get this safe and sound to your door.

**The last photo is a view through this eyepiece in my late 1981 Celestron C80 at 57x. We are looking throug a classic Vixen doublet achromat and as you can see, secondary spectrum is suppressed fantastically with this Orthostar on the team. Across the entire visual plane, you will see a marvelous, tightly-resolved image with wonderful, true color. This is why we love these eyepieces so darn much.**

This Orthostar you see here marks the final generation of the (4) known. The 1st gen models are heavy with a thick gauge of milled brass in the chrome barrel. On that barrel, it will have the deep etches "ORTHO-STAR" vertically appearing on the barrel.
The 2nd gen models will feature the same, heavy chrome lower body, but now "ORTHO-STAR" no longer appears on the chrome. Instead, on the black body, the vertical etchings "16 MM" is seen.

The 3rd gens will appear like the Meade Research Grades with the very lightweight, brilliant aluminum lower barrels. The only brass is now in the internal, flocked lens retainers. The volcano shape of the black body has sharper bevels and the lower portion that threads to the milled barrel has a more pronounced skirt. On the black body "OR 16mm" is etched.

And finally, we come to this model here, which postdates 1975. It looks so much like a Meade RG Ortho, it could pass for one with "Meade" or "MEADE" etched in white on the bevel. Instead, however, the only reference to anything is a white "16 mm" etch. Unlike Meade, which would have "JAPAN" in a ghosted etch on the black body, this era of the Orthostar will have "JAPAN" etched on the base retaining ring, which supports the bottom most element.

Of course, to the master collectors of these remarkable orthoscopics both from Cave, Meade, Bushnell, and Optical Craftsmen (yes, the Connoisseur Series!!!), we know there was never a 16mm RG created after 1976 (they are very hard to locate). But if you wanted one, this will fit that collection!

Model:  Orthostar 16
Barrel size:  1.25-inch
Focal length:  16mm
Design:  4-element orthoscopic (3)(1) configuration
Optics:  fully coated
Field of view:  45 degrees
Eye relief:  9mm
Exit aperture:  14.0mm
Threaded for filters:  no
Materials:  milled aluminum, brass, glass
Weight:  2.0 ounces

We should also remind the collector that these 16mm orthoscopics in particular was a much loved, fixed ocular on the legendary Bushnell Spacemaster II 60mm, which was a 60mm f/6.67 that operated with a fixed 25x orthoscopic eyepiece. 

Though this "RG Class" orthoscopic does not feature the multi-coatings as we saw with Meade by the 1977, it is nonetheless a benchmark ocular. This is the perfect focal length for zooming in on galaxies, trying to split your fainter globulars, and finding pinpoint appreciation in open clusters while forgoing the mega wide angle field experience in the more complicated, heavier eyepieces of today. They will get it all in, but will they be as finely resolved in your apochromat? Hmmm.....

You'll want this in your accessory tray when traveling to a half phase Moon, The Whirlpool, Edge On, and Black Eye galaxies, M52, NGC 457, M37, M11, and The Ring of the Double Cluster, and you won't want to miss The M46 Donut, The Swan, The Eskimo, The Ring, and The Orion nebulae. If you fear the tight eye relief of going to the lower focal oculars, just drop this into your Celestron Ultima or Meade 140 2x barlow; you'll be at 8mm with well over 12mm of eye relief!
Now you can travel up close to Jupiter, Saturn, The Moon, or Mars in your telescopes of great legend; like the Takahashi FC-100N, Celestron Ultima 8 PEC, Jason 324 Saturn (hybrid diagonal), Meade 826C, Orion VX 102 Fluorite, or the Cave 6 Student DX. 

Cosmetics on this ocular is not wholly collectible, but, then again, you can't just go out and get any Orthostar (or Connoisseur) you want in any condition these days. The photos will bear witness there are no dents or flat spots or deep dimples on the cylinder form. The knurled grip ring is uniformly crisp with no smoothening...And you will see our favorite "JAPAN" etch on the top lip of that ring in minty presence. The black body is uniformly black all the way around with no fade or shallowing of the color. There is paint wear on both edges of the bevel, which is no surprise given it has lived 5 decades with the humans. The cream-white etched characters are perfect and unworn.

The optics are in great condition as it sits and for its age; well taken care of, but not preserved and untouched. And, as the photo shows, it can resolve like a champ.
There is a very faint layer of haze that is highly likely between the top face of the bottom element and the bottom face of the 2nd element. The top (3) elements are cemented, so haze getting into that area is unlikely. There is a coating spot in between the top and middle element and the coatings on the top-facing element show minuscule pittings in sporadic areas on the edge peripherals. 
So, all this aiming to a well-enjoyed ocular that was responsibly handled.

Those of you who loved these specific types of oculars know they were gone forever by December of 1985 (Meade) and never destined to return. In fact, the optical firms that created them would not be able to recreate them today anyway. Having one of these eyepieces in your accessory tray or carry case, on a mission to see the stars with you tonight, also carries with it a special feeling of owning a remarkable piece of Cave history.

All nations welcome to bid.