The $4 Takumar 50/1.4
I get almost all of my vintage lenses from estate sales... but this one was a particularly notable find. The camera it was apparently used with was already sold when I got there, and I happened to randomly run across it elsewhere in the sale. No price tag, so I brought it to the cashier and asked; she looked at it for a moment, shrugged, and said. $4. <grab>
I've already got a couple copies of the Super-Takumar 50/1.4 - including both the legendary 8-element version and a de-yellowed 7-element version*, in addition to the Super-Multi-Coated 50/1.4. So it was a lens I already had... but for $4, I couldn't resist, and at worst I figured I could pass it along to a deserving soul.
20260818-SDIM1504v1.dng by
Travis Butler, on Flickr
Sigma fp, Super-Takumar 50/1.4 (yellowed)
Was taken just after sunset, so the lighting wasn't that good... but still pleased by the results.
*For those not familiar with the 50/1.4's history... the original 8-element Super-Takumar
was designed in the mid-60's as an absolute best-of-the-best lens to demonstrate Pentax's ability to stand on the same ground as premium lens makers like Zeiss. Because of its complex design, it was very expensive to make - many sources claim it sold for less than its manufacturing cost - and after a couple of years, it was replaced by a simpler 7-element version. To keep the IQ high, the original 7-element version was designed with a thoriated glass element, and radioactive decay yellowed this element over time. The yellowing can be reversed with a strong UV light source; I used a LED lamp from IKEA, which cleared my original copy in about a week.
In the early 70s, the last generation before Pentax switched from M42 to K-mount, they introduced a Super-Multi-Coated version of the 50/1.4 with improved coatings; I don't notice that much difference, but I rarely shot it in situations where flaring was an issue. According to some reports, they also were able to eliminate the radioactive element; they also changed the focus ring, from an all-metal hills-and-valleys design to a rubber grip.
The later SMC version is on the left; the original metal ring is on the right.