Oscillo Navitar - yet another mystery lens

[Jan Becket]

Someone gave me an Elgeet 86mm f.1.2 Oscillo Navitar. It makes a great paperweight, but I wonder if itʻs good for anything else. Iʻm guessing it’s a flat field design maybe for reproduction or scientific lab work. It stops all the way down to f/11. Anyone here ever used one? Image circle?

[After posting the question above, I had the whim to get out the PalmRAD meter I got a couple of years ago, after Fukushima. Held up to the lens it went wild - recorded 1,500 CPS (Bq), or something around 180 microseiverts / hour. By way of comparison, the background here is .015 uSv/hr. Now Iʻm glad I never tried to use the thing. The question now is how to dispose of it.]

[Dave Grenet]

I imagine it's an oscilloscope camera lens designed to do 1:1 onto 3x4 instant film. I'd suggest that it might make a decent loupe but given the second part of your post I really wouldn't be holding it up to my eye...

[Leigh]

Standard 'scope displays at the time that lens would have been sold were 5" diameter.
The associated cameras were designed to take 1:1 images of the trace and graticule, normally 3"x4" as Dave said.

Oscilloscope lenses are best suited for holding papers on the desk when it's windy.

They are indeed flat field, but they're designed to work at 1:1 and that's all.

- Leigh

[rdenney]

Standard 'scope displays at the time that lens would have been sold were 5" diameter.
The associated cameras were designed to take 1:1 images of the trace and graticule, normally 3"x4" as Dave said.

Oscilloscope lenses are best suited for holding papers on the desk when it's windy.

They are indeed flat field, but they're designed to work at 1:1 and that's all.

- Leigh

And furthermore, given that they are photographing fat but (sometimes) faint 'scope traces with zero magnification or enlargement onto low-acutance materials, they needed to be fast but not that sharp.

Rick "suspecting most o'scopes these days only need 'Print Screen'" Denney

[Jim C.]

[After posting the question above, I had the whim to get out the PalmRAD meter I got a couple of years ago, after Fukushima. Held up to the lens it went wild - recorded 1,500 CPS (Bq), or something around 180 microseiverts / hour. By way of comparison, the background here is .015 uSv/hr. Now Iʻm glad I never tried to use the thing. The question now is how to dispose of it.]

Seal it in a lead lined concrete box and drop it in the Marianas Trench ?
;)

[Struan Gray]

One further count against oscilloscope lenses: they were sometimes only corrected for green light, as most oscilloscopes used green phosphors.

Oh, and one more: some had curved fields of focus to match the curvature of the typical cathode ray tube of the time.

They were in fact highly optimised, just not for photography :-)


But try it. You never know, it might be pictorialist heaven.


As for the radioactivity: it's real, and it will harm you if you sleep with the lens, or carry it around day in, day out. Put it in the basement or attic (away from your film supplies) and it will make an undetectable difference to your background. The radioactive element(s) are already safely encapsulated in glass, so there's little to no chance of environmental contamination.

European towns and city authorities usually have a radiological protection officer, who will often take radioactive items off your hands for free just to get them out of circulation. I seem to remember from the various Aero Ektar threads that most recommend putting a radioactive lens into landfill, but it's probably best to check, not least because these things change all the time.


PS: it occurs to me that given the application the radioactivity may come from luminous paint on some of the controls. In which case there is a slightly higher risk of dust and particles flaking off, and migrating to your lungs. Not good. Look for greenish-white lettering on any controls or dials.

[Jan Becket]

Many thanks for the detailed info about oscilloscope lenses, which indeed seem to be without any conceivable use for large format photography. If it were not radioactive, Iʻd keep it as a paperweight object. Although the amount of radioactivity the lens emits is not huge, thereʻs no sense in adding to overall exposure — readings for background exposure begin to rise about three feet away, and 1,500 Bq/second is not nothing. Years ago I acquired a Linhof 150 Apo Lanthar, which I understand was manufactured with similar glass. That one was hard to part with, but now Iʻm glad I did. Iʻd rather save the discretionary exposure for things like flights to Europe.

After some phone calls today I found that the expenses of disposing of a radioactive object are huge, and entail specialized packaging and a flight to an approved landfill on the US continent. Fortunately for me, the state dept. of health radiation unit agreed to take the lens, which they say they can use for training. So in the end, the thing has a use after all.

[Harold_4074]

It is entirely possible that the lens has, rather than a radioactive optical element, radioactive contamination from the Pacific nuclear tests of the 1950s. The Navy supported those (enormous) projects from Hawaii, and it is not beyond belief that some sailor or civilian "liberated" an oscilloscope camera before the rest of the gear was junked. (The standards of risk were in those days a bit less stringent.)

I know someone who worked on the Amchitka (Aleutian Islands) nuclear test; it seems that the folks there could have pretty much any souvenir they wanted shipped home at government expense, as long as it was not explosive or a heavy weapon (with which the island was well supplied, thanks to WWII). It seems unlikely that anyone in the shipping end of things would have worried about a piece of junk being mildly radioactive.