Got a couple lenses that I can't figure out

[Nick Ahlgrim]

I bought a box of lenses for $19 and have two from the box that I cannot find out what they are from. Most of the lenses look like they are for some industrial purpose.

The first one is a Topcon 280mm. The front element is about 73mm and is coated, rear element is about 39mm and is also coated. The rear mounting thread is 52mm and the lens is about 42mm long. First I put it on my 4x5 and it made a nice sharp looking image. Then I wanted to see how big of an image it make, since it looks far too large for a 4x5. It ended up projecting a very sharp large image onto white poster board (around 15x20" from about 13in away.) I don't have a Ulf yet, so I had to do it outside looking into my lit up room through the curtains.

I cant find anything about this lens online. Thinking it probably had some industrial use, but I have no idea what.

The second one says "Made in Germany" and I don't know the focal length yet. It also made a really nice looking image on my 4x5. Its smaller then the Topcon. Front element is about 29mm and the rear is 27mm. The barrel has a diameter of 47mm and is 41mm long. Rear threads are 43mm.


Hoping someone on here knows somethings about either of these lenses. The Topcon looks real nice and I would love for it to turn out to be a good lens.

Any help is appreciated.

[Jim Graves]

I believe TOPCON = Tokyo Optical Company ... here's a link: Link

[Nick Ahlgrim]

I believe TOPCON = Tokyo Optical Company ... here's a link: Link

Thanks. I know about the company and have owned a couple lenses in the past. Its just this lens that I can't find any information on. I've read that the company is huge in industrial optics, so that is what makes me believe it might not be a photographic lens. I'm hoping someone knows about this lens in particular or what type of lens it is.

Thanks for the link.

[Wimpler]

The Topcon is an F-theta lens used for laser marking. That should help on finding more info.

The other lens looks a bit like an eyepiece of some sort of optical device.

[Michael E]

The tread on the second one seems too coarse for fastening the lens. It might be a projection lens with a focusing helicoil.

[cdholden]

The tread on the second one seems too coarse for fastening the lens. It might be a projection lens with a focusing helicoil.

Possibly an eyepiece? Lots of Zeiss and Leitz microscopes came out of Germany. All of the Zeiss optics I've seen have their name clearly marked on the side. I'm not familiar with Leitz enough to say the same for them.

[Nick Ahlgrim]

Thanks for the help.

-Tried looking for F-theta lenses that match, still haven't found one. Knew it was going be something like that, although I'm still not exactly sure what an F-theta lens is. Going to look for a little while longer, then I'm throwing in the towel.

-A bunch of the other lenses that came in the box look like eyepieces for something, so thats probably right.

Sure I can figure out something to do with them.