Asahi SMC Takumar 50mm f1.4 - Autumn Walk
It was a cold, brisk morning, the kind where the leaves have all fallen from the trees and you can sense that winter is just a few days away. Welcome to late autumn in Canada. It was a great day to hit the trails and enjoy the warm weather. I say "warm" as in above zero, it was only 5°C (41°F), but still, it felt good to be outside. I was in the mood to have a little fun, so I decided to take out a vintage lens out for a spin. Today I chose the Asahi Super Multi-Coated Takumar 50mm f1.4.
The main reason I chose this lens on such an overcast autumn day, is because of its unique yellow radioactive glass. I was hoping that the yellow tone of the glass would help make the warm colors pop. I wanted my images to feel more vibrant and warm, kind of how a Tiffen Enhancing filter works. It seemed like the perfect lens for this type of day. The images certainly suggest that the lens did the trick.
What makes this lens so interesting is the use of a radioactive metal called thorium in its glass elements. Thorium was added to improve light transmission, and it’s said to make images sharper and more contrasty. Over time (this lens was released in 1971), the thorium reacted with the glass, causing the distinct yellowing seen today. Using Thorium was a common practice for several lens manufacturers back in the 1960-1970s, but for obvious reasons, it was eventually banned. You can still find these old radioactive lenses on eBay from time to time, and they’re pretty easy to spot, just look for the yellow glass. It’s a really unique piece of photographic history. From the information I’ve been able to find about this lens the radioactivity isn’t high enough to cause immediate health concerns. Obviously store it in a container and don’t leave it setting beside you on your desk all day as you work.
The yellowing can be reversed by exposing the lens to intense UV light. I considered removing the yellow cast from the lens but I decided not to mess with it. I think it’s pretty cool to have this piece of optical history in its original form, it only ads to it’s unique charm.
Here are some sample shots I took with the Asahi Super Multi-Coated Takumar 50mm f1.4 mounted on my Canon EOS R5 Mark II. Most of these shots were taken around f4 or higher to get a good depth of field and maintain sharpness. Overall, I’m really happy with how the lens performed. It’s been a lot of fun shooting with it, and the results speak for themselves.
