When I came across this lens on Ebay for only $10 (with free shipping) and I saw Tominon engraved on the barrel it was easy to hit the buy-it-now button. Its a Tominon after all, they are almost always sharp and very well corrected for chromatic aberration and designed for copy and macro work. I would guess this lens was made for a microfiche viewer of some kind. Due to the slow f/4.5 maximum aperture I would keep the reproduction ratio at about 2:1 even though the lens is engraved 32x.
This lens is not as common as the other Tominons made for the the Polaroid® MP-4+ technical camera system in the 1970s but they do appear on Ebay from time to time.
PERFORMANCE AND HANDLING
My favorite thing about this lens? The weight and size. Even with all of the adapters and extension tubes, the weight and size was perfect on a mirrorless body like the Sony A6300. This lens really is a fun lens to use on a compact body, so this lens gets my recommendation, at least for performance and handling.
IMAGE QUALITY
First the bad news, the 17mm and 35mm Tominons are excellent performers, this one is not in same class. But the good news is that the 26.9mm is perfectly okay. The images are clean and sharp and at the very least its well corrected for lateral and bokeh CAs, better than the average enlarger lenses, and cheaper.
These images are un-cropped and were made hand-held with a Sony A6300 and a diffused Godox TT350 flash at 1/160th second holding the camera in one hand and the flash in other ( okay I was too lazy to look for my flash bracket).
Click on any image below to launch a new window with a larger version. You can right click, or two-finger click with a Mac and select the open in a new tab or new window options.
Coca-cola can abstract with Tominon 26.9mm lens at 2x
Nice smooth bokeh and good micro-contrast/rendering with and pretty good APS-C sensor coverage.
Coca-cola can white abstract with Tominon 26.9mm lens at 2x
Note the lack of LoCAs in the image below, sharpness is pretty good overall. Nice image quality for only $10.
Rodenstock lens cap details with Tominon 26.9mm lens at 2x
The 17mm and 35mm Tominons cost a little more but are very good performers with image quality that compares to the Canon MP-E 65mm f/2.8 1-5x at 4x with similar sharpness, and much better CA suppression. A detailed review of the 17mm and 35mm Tominons is available here on Closeuphotography.com;
https://www.closeuphotography.com/tominon-17mm/
https://www.closeuphotography.com/tominon-35mm/
MECHANICAL QUALITY
No problems here, the Tominons 26.9mm has an all-metal barrel and simple design so there isnt much to go wrong with this lens.
PRICE/PERFORMANCE
The Tominon 26.9mm lens can sell for somewhere between $10-20 online so they are going to be hard to beat from a price vs performance ratio.
AVAILABILITY AND COST
The 26.9mm Tominons pop-up on Ebay from time to time and since the lens has no mount, and and are unkown, they sell for almost nothing. I paid $10 for this unit with free shipping and as of July 2018 there is one sitting on Ebay now for $14 with free shipping. Use the search terms Tominon 26.9mm lens.
Tominon 26.9mm lens with SM1 threaded sleeve.
TECHNICAL SPECIFICATIONS
Tominon 1:4.5 f=26.9mm 32x - 165 lens
Type: Reproduction/Microfiche
Focal length: 26.9mm
Optical Design: Unknown
Manufacturers recommended magnification range: The lens has 32x engraved on the barrel but I doubt that is the real reproduction ratio that the lens is designed for.
Real world magnification range: The lens seems to perform okay at about 2x. Due to the slow maximum aperture of this lens performance would drop off past 3X. For better results at a higher range I would recommend the 17mm f/4 Tominon instead of this lens, or even better, a microscope objective.
A detailed review of the 17mm Tominon is available here on Closeuphotography.com: https://www.closeuphotography.com/tominon-17mm/
For a detailed review of the $17 4x objective see this article on Closeuphotography.com: https://www.closeuphotography.com/seventeen-dollar-plan-4x-objective/
Coverage: Covers APS-C at 2x.
Working distance: Short
Aperture range: f/4.5
Lens mount: none
Mounting: The Thorlabs SM1 threaded sleeve slips over the barrel and with shim tape the fit is tight.
Filter thread: none
PROS AND CONS
What I really like:
Tiny light and compact design perfect on a mirrorless body
Chromatic aberration suppression
Outstanding price/performance value
What I dislike:
No lens mount
Conservative maximum aperture
SET-UP FOR MACRO PHOTOGRAPHY
Mounting this lens was is easy. I happened to have an extra Thorlabs SM1 threaded sleeve, called an SM1 male to male lens coupler. The inside of the sleeve was just big enough so that the lens could slide right in. I used some shim tape to give it a tight fit. Works perfectly.
Thorlabs SM1 parts and adapters used to build the set-up above, L to R:
Thorlabs SM1 Coupler sleeve; https://www.thorlabs.com/thorproduct.cfm?partnumber=SM1T2
Thorlabs SM1 Coupler lock ring. Included with the coupler.
Thorlabs SM1-threaded (1.035"-40) adjustable lens tube with lock ring.
Thorlabs SM1-threaded (1.035"-40) lens tube.
Thorlabs SM1-M42 x 1.0mm adapter.
E-Mount Mount Adapter to 42mm x 1.0 threads. A common, cheap Chinese threaded adapter worked perfectly.
Tominon 26.9mm lens with Thorlabs SM1 threaded collar.
THE BOTTOM LINE
For $10-15 this is a perfectly okay lens but I wouldn't recommend one since its not the easiest lens to mount and since there are lots of other excellent lenses in the 2x range, including other Tominons, for a just few more dollars. It beats most enlarging lenses chromatic aberration control, as most Tominons do, which is nice to see.
The 35mm Tominon image quality beats this lens and costs just slightly more, maybe $35-60, but these suffer from a large sample variation issue. I had to buy 4 Tominon 35mm lenses before I found an excellent one.
For a few more dollars, a couple of hundred actually, the Minolta DiMAGE Scan Elite 5400 image quality is unbeatable: https://www.closeuphotography.com/minolta-dimage-scan-elite-5400-lens/
THE HISTORY OF TOMINON
Tominons were made in Japan by Tomioka, which later became part of Yashica, and finally part of Kyocera. Tomioka is still around but they are now part of Kyocera-Optic Japan Co., Ltd. The original Tomioka plant is the same factory where Contax lenses T*, Zeiss’s flagship 35mm lenses, were manufactured under contract for Carl Zeiss Japan.
From the Kyocera-Opticcompany website:
Kyocera Optec, originally founded in 1949 as Tomioka Optical and Mechanical Manufacturing Co., Ltd in Ome City, Tokyo, has constantly developed leading-edge lens manufacturing technologies since its early days. In 1974, the Company started manufacturing Carl Zeiss Lenses for Contax cameras through technical support from the Carl Zeiss Foundation in Germany; which were regarded as being among the world's highest quality lenses. Since joining the Kyocera Group in 1983, the Company has diversified its product focus and brought new standards of excellence to a wide range of optical equipment manufacturing fields.
LINKS FOR MORE INFO
Tomioka, the maker of Tominon lenses is still around, but they are now part of Kyocera-Optic Japan Co., Ltd.
http://www.kyocera-optec.jp/english/company/
More info on Tomioka on Camera-pedia site:
http://camerapedia.wikia.com/wiki/Tomioka