Vintage Lens - Island in the Net

I'm experimenting with some vintage Asahi lenses and Fotodiox adapters. I have my father's non-working Asahi Optical Co. Spotmatic II which, after he passed earlier this year, became even more precious to me. My first film camera was a Pentax P3 which I still own. Earlier this year (2019), as a tribute to my dad, I bought an Asahi Pentax Spotmatic II on eBay with an Asahi Optical Co. SMC Takumar 55mm f/2, and I have slowly started to re-learn film photography.

I also bought up a Fotodiox Lens Mount Adapter Compatible with M42 Screw Mount SLR Lens on Fuji X-Mount cameras lens adapter that I can use these on my Fuji X-T2.

Many websites keep propagating the “story” that a 50mm focal length on a 35mm full-frame camera is roughly equivalent to the field-of-view (FOV) of the human eye. The statement always seemed odd to me given that when I look straight ahead, keeping my eyes from moving side-to-side, I see “wider” than 50mm FOV. The “50mm is standard” mantra also seemed strange, given what I had learned about FOV in graduate school during my “vision” classes. We were being taught about the human eye because designing displays and image processing algorithms requires an understanding of the human vision.

The focal length of the eye is 17 or 24mm however, only part of the retina processes the main image we see. This part of the retina is called the cone of visual attention which is about 55º wide. On a 35mm full-frame camera, a 43mm focal length provides an angle of view of approximately 55º. The 43mm focal length closely approximates the angle of view of the human eye.

43 is not roughly 50. That’s a round-up of nearly 14%. And then saying 52mm, when using a 35mm focal length on a crop factor camera, is close enough to 50 mm compounds the error.

Maybe it’s the engineer in me, but these sort of “errors” get passed around and become “law”, and then we get stuck with them¹.

It was with the 43mm focal length in mind that I purchased an Asahi Optical Co. Super-Multi-Coated Takumar 28mm f/3.5 lens. This 28mm lens, when mounted to a Fujifilm X camera, provides a 42.56mm (28×1.52) full-frame equivalent field of view which is near enough to the actual visible focal length of the human eye.

My purchase came directly from Japan with the lens in a leather pouch along with the lens hood in another leather pouch.

On my Fuji X-T2, this lens has a 42.6mm full-frame equivalent field of view which is near enough to the visible focal length of the human eye, making this an excellent lens for travel and street photography. Between 1962 and 1975, Asahi Optical Co., which eventually become Pentax, manufactured a various version of the Takumar 28mm f/3.5 for its range of Spotmatic cameras. This version of the lens was produced with a multi-coated layer designed to reduce lens flare. The lens was sold from 1971 to 1975 and was given the Super-Multi-Coated label.

The first time I used this lens was during my trips into Philadelphia for daily radiation treatments for my Graves Eye Disease. After each treatment, while I waited for the valet to bring the car around, I would stand on the street and take photos. I have used the lens mostly for street photography ever since. Street photography was something I hadn’t done much with other cameras and lenses, but learning how to use this lens was a big help. Instead of pointing the lens at people, I practised by looking down at the flip screen to use focus-peaking, which I think made me seem less threating as perhaps some people thought I was using a film camera.

Like most Asahi lens from the era, the Super-Multi-Coated Takumar 28mm f/3.5 is all-metal and glass construction. It feels solid in the hand and compliments the look and feel of the Fujifilm X-T2. The focus ring is silky smooth, and the aperture ring gives noticeable clicks as it moves through the half-stops. The lens has a 49mm filter ring and comes with a plastic lens hood. The lens has a maximum aperture of f/3.5, and the minimum aperture is f/16, with intermediate stops at ½ increments. This lens is not a lens for bokehlicious photography. The Asahi Optical Co. Super-Takumar 55mm f/2 is a better choice for that. Most of my images were shot at f/5.6, which works well for street photography but also seems to be one of the sweet spots for sharpness in this lens. Because the lens is not able to communicate with the electronics in the Fujifilm X-T2, when I attach vintage lenses, I tend to shoot the glass at one aperture setting to make it easier for me to add that metadata to the image later.

I know not everyone will be as into vintage lenses, and losing access to auto-focus is a deal-breaker for some. Still, if you do have an interest in trying out older lense, the Asahi Optical Co. Super-Multi-Coated Takumar 28mm f/3.5 is highly recommended. The lens is inexpensive, and both the build quality and image quality are great. The Super-Multi-Coated Takumar 28mm f/3.5 is my second Asahi lens and probably won't be my last.