Tuesday, April 9, 2013

Make Your Own Topcon Mount Adapter

Since I got the Topcor lenses from the camera show, I have fallen in love with these lenses. I do have other Torcor lenses before these ones, but they come in a completely different mount; not the modified Exakta mount, but one that has aperture control on the camera body, a la DKL. This particular mount, like the Exakta, does not provide a secured and tight fit when a lens is mounted; except it's worse than Exakta. The lenses themselves are well made and I have been scratching my head for months on how to mount them to my camera. As far as I know, nobody makes a mount adapter for it.

The other Topcon - very similar to the DKL mount. Aperture control is on the camera body.

Today it dawned on me that I had a broken Topcon body. Why not make an adapter from the original mount? Why didn't I think of that before? Well, in fact, I tried this with a Kodak Reflex with DKL mount, but no cigar. The mount is too intricately intertwined with other parts of the body that it was difficult to separate the mount with the aperture control intact. But, what have I got to lose? It didn't take long before sweet success arrived! The mount is much simpler than the DKL and aperture control stays unaffected after mount is removed from the body.

Gruesome body parts. The mount we want is on the right.

After the mount is removed, I JB Welded a 58-49mm filter ring (don't have a 58-52mm handy) to the rear of the mount, added a 49-52mm step up ring, and mounted the adapter to the very thin focus helicoid. Very unfortunately, I can't use my favourite Yeenon helicoid as the mount is about 2mm too thick. How I wish I had a metal lathe to shaved off these two millimeters. But, this will do in the meantime. The mount adapter is not perfect. the filter ring I glued/welded on is slightly jagged and is not completely flat, cause the left side of the picture to be slightly softer than the right side. I will need to find a better solution for this. It's workable for the time being.

UV Topcor 35mm f3.5 with mount on helicoid. Note the filter rings.

The other Topcors: Mount, 53mm f2, 35mm f3.5, 135mm f4.

Gorgeous, eh?


  1. Well done!
    These lenses are relatively cheap due to the fact there are no ready made adapters, but don't design the Lens Bubbles Mk II to easy to make as it'll push up the prices. :-) I don't have these myself but have considered getting a few with an old body to adapt.
    Comments on MFLenses have said that these lenses are ok and maybe not worth the effort to adapt when there are others of equal quality cheap enough. But I know that you like the challenge and then the pleasure of seeing the results of your efforts.
    Nice to see that you're putting pictures of your featured lenses on the posts too.

    1. GaryB: These lenses are average performers, as they were designed to be cheap. They are probably not worth buying for conversion, unless, you can get it for next to nothing, or already own them. Nothing pains me more to see lenses around me that I can't use :)

  2. Hi,

    love your lens tests. Check out this adapter:

    Very Russian, but it works well for me. I don't think they have for Nex though.


    1. Ingenious! Those screws make me cringe, though. If I have expensive and mint lenses, I wouldn't want those screws clamming down on the lens. Perhaps they should use plastic screws.

    2. For anything worth something I have specialized adapters, but this one is great for toying around. I should look into plastic screws though. Should be easily replaceable.

  3. I like your blog! I find an easy and cheap way to make a Topcor UV to M42 adaptor. Please see the following link. (I hope you can read Chinese)

  4. I made 14 UV Topcon to m42 adapters, keep two to convert my lenses to standard 42 mount. Sold 12 on ebay to share with Topcon fans. People are very happy to use them. I created a group in flickr, for people exchange their experience of UV lenses. Please visit and join discussion at: www.flickr.com/groups/topcon

  5. Great idea, use for these ole lenses.

    I made a reverse adapter (macro)for my 53mm/f2, using the camera mount to allow me to control the lens. My adaption allows me to use ALL f-stops, f2 to f22.

    I have on order a auto-100 body w/ another 53mm/f2 lens, and a exacta MFT adapter. I plan to remove the exacta part and mount the Topcon camera mount in its place. I plan to use if for close up photography, so infinity focus is not important.

    BTW I had made an adapter using plastic, got a couple great shots, one in 3D before it broke....

  6. These lenses look remarkably similar to the Kowa SER2 lenses my uncle gave me. I'd love to adapt them to my Sony mirrorless E-mount. Any suggestions on how to accomplish this?