Pekka Buttler, 08/2024
Specifications
The table below summarizes the lens’ key specifications (measurements based on pictured, last version of the lens):
| Brand: | Tokyo Kogaku (Topcon) | Lens name | UV TOPCOR 1:4 f=135mm |
| Focal length(s)1 | 135 mm | Angle-of-view2 | 18,2 ° |
| Maximum Aperture | f/4 | In Production | 1964–1978 (all versions) 19693–1978 (this version) |
| Lens mount (this lens) | Topcon UV | Generation | Topcon UV |
| Length4 | 83,8 mm | Diameter5 | 62,7 mm |
| Filter ring diameter | 49 mm | Weight | 317 grams |
| Lens element count | 4 | Lens group count | 3 |
| Aperture blades (S/R/C)6 | 5 S | Focus throw | 180 ° |
| Minimum focusing distance | 1,8 m | Maximum magnification | 1:12,9 |
| Has manual aperture ring | NO | Has Manual focus ring | YES |
Further notes:
• This lens is the second Topcon UV 135 mm f/4 version. See below.
• This version II of the Topcon UV 135 mm f/4 is a relatively compact 135 mm lens that has the Topcon standard filter thread diameter (49 mm).
• As with all Topcon UV lenses, this lens lacks an aperture ring (aperture was controlled on the camera). This has some implications for adapting (see below)
• The filter threads do not rotate on focusing.
• The Topcon UV 135 mm f/4 (II) lens offers a rather generous integrated, extendable hood (see below).
Versions and variations
While Topcon continuously tweaked its offering regarding standard lenses for the Topcon UV system (53/2 -> 50/2 -> 50/2 -> 55/1.8), the lens lineup remained otherwise untouched from introduction to discontinuation of the entire lineup. With one exception: the 135 mm f/4 design.
Here Topcon manufactured two clearly distinct lenses that had the same mainline specifications.
| Lens name | UV TOPCOR 1:4 f=135mm TOKYO KOGAKU JAPAN | UV TOPCOR 1:4 f=135mm TOKYO KOGAKU |
| Serial numbers start | 110 | 139 |
| Version | Version – I | Version – II |
| Years7 | 1964–1969 | 1969–1978 |
| Optical design | 5 elements in 5 groups | 4 elements in 3 groups |
| Filter thread diameter | 58 mm | 49 mm |
| Weight | 305 g | 305 g |
| Lens hood | thread-mounted | integrated |
Besides the later lens being more compact and in line with the 49 mm filter thread typical8 of Topcon UV lenses, I have no concrete information on why Topcon decided to redesign the 135 mm f/4 lens.
History of Topcon
Unless you know your camera lore, you might not know that Topcon was once – between 1957 and 1976 – one of the foremost camera companies in the world.
You can read more details in the Topcon company profile.
Adapting
Adapting Topcon UV lenses is not especially easy, but this is not so much due to the lens mount. Technically the Topcon UV mount is very much like the DKL mount, and adapters for the DKL mount have existed for ages. Moreover, the Topcon UV mount offers a generous flange focal distance, making it relatively easy to manufacture adapters, even to SLR mounts.
The real reason why adapting Topcon UV lenses is relatively difficult is the simple weak availability of suitable adapters. It seems practically no-one bothered manufacturing adapters to allow the use of Topcon UV lenses on SLRs, and even with today’s most popular mirrorless mounts, you have to dig deep into aliexpress to find a metal adapter from Topcon UV to Sony FE/NEX (eBay has some 3D printed adapters).
(Remember that because Topcon UV lenses lack an aperture ring, that is a functionality that the adapter must supply.)
With these limitations in mind, below are (in the current state of affairs) the situation for adapting Topcon UV lenses.
This lens cannot be used natively on any current SLR or dSLRs. To use it in its native environment, you will need a Topcon UV (Wink Mirror S, Uni, Unirex/Unirex EE, IC-1 auto or new IC-1 auto) film body. While these were never produced in immense numbers, they seem to have stood the test of time reasonably well, and can still be found in a functioning condition.
While Topcon UV lenses are manual focus lenses, they lack an aperture ring. Hence, to adapt a Topcon UV lens to a mirrorless camera, you need an adapter that not only offers the correct mounting system and flange focal distance, but also allows you to control the Topcon UV lens’ aperture mechanism. As noted above, such adapters are available, but their availability is surprisingly weak. No special adapters (helicoid adapters, tilt/shift adapters) are currently available.
Using Topcon UV mount lenses on an SLR/dSLRs could be an option (there are no physical reasons why the mount could not be adapted), and Topcon themselves used to offer an adapter allowing the mounting of Topcon UV lenses on Topcon RE cameras. However, it seems that there are currently no adapters available. Moreover, as the rearmost element of many Topcon UV lenses protrudes significantly beyond the flange, it is not inconceivable that some Topcon UV lenses would (assuming there was an adapter) risk colliding with the mirrors on some dSLRs.
Footnotes
- Focal length is (unless stated otherwise) given in absolute terms, and not in Full-frame equivalent. For an understanding of whether the lens is wide/tele, see ‘Angle-of-view’. ↩︎
- Picture angle is given in degrees (based on manufacturers’ specs) and concerns the diagonal picture angle. Rule of thumb:
> 90 ° ==> Ultra-wide-angle
70–90 ° ==> Wide-angle
50–70 ° ==> Moderate wide-angle
40–50 ° ==> ‘Standard’ or ‘normal’ lens
20–40 ° ==> Short tele lens
10-20 ° ==> Tele lens
5-10 ° ==> Long tele lens
< 5 ° ==> Ultra-tele lens ↩︎ - It is unclear at what stage Topcon introduced the II-version and discontinued the first version. Sales brochures and manuals for the Topcon Uni (1964-1969) still show the I-version, whereas sales brochures and manuals of the subsequent Unirex camera already show the II-version. ↩︎
- Length is given from the mount flange to the front of lens at infinity. ↩︎
- Diameter excludes protrusions such as rabbit ears or stop-down levers. ↩︎
- S=straight; R=rounded; C=(almost)circular at all apertures. ↩︎
- (See footnote 3) ↩︎
- The only Topcon UV lenses that did not use the standard 49 mm filter thread were the UV 200mm f/4, the UV 87–205mm f/4.7 zoom and the first version of the UV 135 mm f/4. ↩︎