**The Radioactive Eye:** A look at the front element of Serial No. 3973263. If you look closely at the glass, you can see the distinct amber/yellow tint caused by the decay of the Thorium elements over the last 50 years. This isn't a defect; it's the lens's natural warm filter.

I’ve always loved vintage images because they lack refinement. They capture unique characteristics—a "soul"—that is often missing in today’s clinically perfect digital photography.

Many modern photographers rely on simulation to get this vibe. They use modern equipment and then stack color grading files, add artificial grain, and crank up the temperature to mimic a look that used to happen organically.

I’m not one for simulation. If I want the look, I want the glass that creates it. That’s why I finally snagged one of the coolest old-school lenses out there: the Asahi Pentax Super-Takumar 50mm f/1.4.

The Hunt for Glass

**Built Like a Tank:** No plastic here. The scalloped metal focus ring and depth-of-field scale are a reminder of 1960s industrial design. The focus throw is long and buttery smooth, making manual focusing a tactile experience.

There is a fine line between an old lens that can be obtained for a minimal price and one that has become rare and fetches a fortune. I took the smart route and picked up the 7-element version (Serial No. 3973263).

According to archival data, this specific lens was manufactured between late 1968 and 1970, likely serving as a kit lens for the Spotmatic SP or Spotmatic II. It uses the M42 screw mount (42mm x 1mm pitch), which was the "Universal Mount" of that era, making it incredibly easy to adapt to modern bodies today.

The Radioactive "Glow"

Here is where it gets wild: these lenses famously "yellow" over time. This isn't a defect; it's physics.

To create a high-performance f/1.4 lens in the late 60s, Asahi engineers used Thoriated glass—glass doped with the radioactive element Thorium. This allowed for a high refractive index, meaning the lens could be sharper with fewer glass elements. Over the last 50 years, the radiation has caused the glass to amber, acting as a natural warm filter that adds incredible character to black and white photos and a nostalgic warmth to color shots.

(Don't worry, the radiation levels are negligible unless you grind the glass and eat it.)

Managing the "Aberration"

Unlike modern lenses that correct every flaw, the Super-Takumar allows some of these light rays to scatter, creating a dreamy "glow" around your subject while keeping the core details sharp. It smooths out skin textures beautifully, which is something digital filters try hard to replicate but rarely get right.

The Manual Experience

**The Secret Weapon:** The "MAN" (Manual) switch is critical for using this lens on modern cameras. Since my adapter doesn't depress the aperture pin, I flip this switch to "MAN" so the aperture blades actually close when I turn the ring. Without it, the lens would stay wide open at f/1.4 regardless of where I set the dial.

One of the most exciting parts of this lens is that it forces me into a manual focus workflow.

In a world of cameras with unmatched auto-focus, I believe users have become accustomed to the camera doing the work—perhaps even a bit lazy. Learning to manually focus on the fly should be in every photographer's back pocket. I’m already finding it to be a fun challenge; the focus throw on this lens is long and smooth, built with a mechanical precision that feels like operating a tank.

The Setup

**Worlds Collide:** Forty years of optical history separate the glass from the sensor. I mount the 1969 Super-Takumar to the 2007 Canon 1Ds Mark III using a simple K&F Concept M42 adapter. It’s a 50-year-old analog soul inside a digital body.

The photos shared below were all taken using my Canon 1Ds MKIII with a K&F Concepts M42-EF adapter. Because this lens features an Auto/Manual (A/M) switch, I can easily stop down the aperture manually without needing a specialized flange adapter—a distinct feature of the Super-Takumar design.

The resulting images might look "soft" to the untrained eye when shot wide open, but that isn't missed focus. That is the haze, the glow, and the history of the lens painting the image.