The shots for this match were taken over two weeks ago. In that time, I've looked at the crops, looked at the full pictures, looked at the lenses, all trying to decide where to start with the comparison. One thing is clear: both the SMC Pentax-A 1:1.2 50mm and the Super-Multi-Coated Takumar 1:1.4 50mm are fine lenses. The are both so fine, in fact, that there is little to delineate between them.

The Pentax-A 50/1.2 has a half stop more light gathering capability than the S-M-C Takumar 50/1.4. It doesn't alter appearances when viewed through a DSLR viewfinder, nor does it result in tremendously varied depth of field, but it is nonetheless a difference. The shutter speeds will be a half stop faster with the Pentax-A 50/1.2 shot wide open than the S-M-C Takumar 50/1.4 in the same state. Does this matter in real world shooting?

Well, maybe. Certainly the difference between 1/45th and 1/30th of a second can mean the difference between sharp pictures or apparent hand shake. Of course, shooting the Pentax-A 50/1.2 at f/1.2, while certainly sharp for f/1.2, isn't going to be accused of being 'tack sharp'. My oft-referred to photo here shows that f/1.2 can indeed be sharp when the focus is nailed. I verified this in a less random setting by examining crops of this image. You can see in the crop here that the plane of focus is quite sharp. You can also see where this lens gets its reputation as being quite soft by examining the crop here. The post, just outside the (admittedly shallow) plane of focus has a soft-focus haze around it. With the incredibly small tolerances involved at f/1.2, focus error is going to taint a high percentage of f/1.2 shots. Of course, the same can be said at f/1.4, because of which I'm going to award a slight edge to the Pentax-A 50/1.2 for the extra half stop.

Both lenses are sturdy metal lenses with long, smooth focus throws. The Pentax-A 50/1.2 is noticeably heavier, but neither lens qualifies as heavy for a lens in general. The Pentax-A 50/1.2 has the obvious advantage of focusing and composing wide open and the camera stopping down only to take the shot. The Pentax-A 50/1.2 also allows electrical control of the aperture and optionally enables the use of one of the K10D's scroll wheels for exposure compensation. The Pentax-A 50/1.2 can be a more convenient lens without sacrificing manual focus use and feel.

You never know when an f/1.2 opportunity is going to arise. The above shot, at 1/30th second, would require about 1/20th second at f/1.4.

I really liked this shot at f/8 during the comparison. Both lenses would do equally well in this scenario.

Lens Rendering Characteristics

Like in the previous comparison, some of the rendering characteristics may come down to lens sample variation. With lenses so closely matched that differences are faint even at 100% viewing sizes, it is highly likely that differences discussed here are not 'field' relevant.

The S-M-C Takumar 50/1.4, like several of my similarly-aged Takumar lenses, shows a much warmer color response. This isn't a problem for RAW shooting, but it does limit your options on JPEGs and film somewhat.

Sharpness was a draw. It was frustratingly hard to get focus points to match exactly (see the crops from the guitar bridge here and the crops from the bicycle here) that I truly just gave up. It is obvious from the crops that both lenses are adequately sharp in their plane of focus, no matter that it was nearly impossible to get both planes in exactly the same spot.

Bokeh was also quite close to a draw. There is a fine (precariously fine, perhaps) line that slightly favors the Pentax-A 50/1.2 over the S-M-C Takumar 50/1.4 based on crops here. In that scene, the Pentax-A 50/1.2 rendered the highlights ever so slightly smoother, although both were marginal at f/1.4 and good from f/2 onward.

Interestingly, the S-M-C Takumar 50/1.4 shows slightly less axial chromatic aberration (color fringing in out of focus highlights). The crops in this color-temperature corrected comparison show that at f/1.4 both lenses have green fringes around the blur discs. However, the Pentax-A 50/1.2 has a slightly wider green ring than does the S-M-C Takumar 50/1.4. Like in the bokeh comparison, both lenses are much better at f/2 and smaller in this regard.

Conclusion

It is a stretch to say that there are field-relevant differences between the SMC Pentax-A 1:1.2 50mm and Super-Multi-Coated Takumar 1:1.4 50mm. Both are excellent to use and produce wonderful images, especially from f/2 on there are few flaws to point out between them. Many people may hold a prejudice towards the Pentax-A 50/1.2, warranted or not, mainly from the romance of the fast glass. Others may prefer the classic 'Best 50mm Lens Ever Made' S-M-C Takumar 50/1.4. I, quite frankly, love them both.

My conclusion is based more on the question: "If I could only keep one of these two lenses, which would it be?" The winner of this match, and the lens heading to the final match against the SMC Takumar 50/1.4, is the same answer: the SMC Pentax-A 1:1.2 50mm.