Handling and Features
Performance
Verdict
Specification
The classic 50mm standard lens is well established as a great option when exploring using older lenses on digital DSLRs. The Asahi Pentax M42 screw thread lenses are probably one of the best-known options, but is the reputation justified and are they really suitable for regular use in terms of handling as well as the quality of results? Here we have a very well cared for sample of the 55mm f/2 Model II lens, dating from between 1971 to 1974. Let's have a close look at what it can do, coupled with the 36mp Pentax K-1.
Asahi Super Takumar 55mm f/2.0 Handling and Features
This particular lens is labelled Super-Takumar, and therefore as being pre-multicoating, but actually there was often overlap with lens manufacture and it could be equipped with the new SMC (Super Multi-Coating). That this might be the case is a view encouraged by the lens having the meter coupling lever that is needed for the Spotmatic F cameras with open aperture metering. The other interesting point is that although the lens is the “budget” f/2 version, this comes from an era where the lenses were the same as the more expensive f/1.8 versions, but with a baffle added to reduce the maximum aperture. Likewise, “budget” camera bodies such as the Spotmatic SP500 would have an unmarked indent on the shutter speed dial that was an uncalibrated top speed of 1/1000 second, just like the more expensive versions.
Starting at the front of the lens, a brief tour first of the various features. There is a 49mm filter thread, and this reflects the compact overall appearance and feel of the lens. What is missing, of course, is a bayonet fit for a lens hood, but the square Pentax snap-on hood PH-SA 49mm for standard lenses is actually still available at £24.99. Second-hand prices will be lower.
The focusing ring us sculpted for grip, and the sheer pleasure of operating the focusing mechanism brings new meaning to the phrase silky smooth. Distance markings in feet and metres are viewed in a cutout on the lens barrel, and there is a useful depth of field scale. There is also an infra-red focusing mark to show the revised distances necessary when using IR film.
The aperture ring has half stop indents and is smooth in operation, running from f/2 to f/16. Behind this is the Auto/Manual switch which selects open aperture and closed down aperture. This is very useful for DSLR metering as set to Auto the diaphragm opens to maximum aperture and focusing is easier. The beep of the K-1 focus confirmation is an added guide to getting the focus spot on. For this to work, the camera should be set to AF. When we are ready to shoot the image moving the lever to Manual will stop the lens down to whatever value we have selected. The alternative technique is to leave the switch on Manual and just use the aperture ring to open the lens up, then count down the steps to set whatever working aperture is desired. It should be noted that some A/M levers will only work when the lens is mounted on the camera, so one that is solidly fixed may not indicate a fault.
Super Takumar 55mm F2 and SMC Pentax FA 50mm F1.4
The screw thread lens mount is devoid of electronic contacts and an adapter is needed to fit the lens to our selected camera body. Screw thread lenses can be fitted via an adapter to almost any camera, but here we have the Pentax K-1 and the ideal is the Pentax manufactured Adapter K. This fits inside the camera bayonet mount. The technique is to fit the adapter to the lens and then bayonet onto the camera. The lens can then be unscrewed and another fitted if desired, effectively temporarily converting a K mount camera body into a screw thread one. The adapter is removed by operating a small lever on the adapter and letting it fall out into the palm of a hand.
The optical construction is 6 elements in 5 groups. Focusing is down to a conventional 0.45m or 1.5 feet and the lens weighs in at a very modest 195g.
Handling is actually very smooth and the only disadvantage over a modern lens is the manual focusing, which may not suit everyone. One tiny operational glitch is the push on lens cap, which if the lens is set to infinity is partially pushed out, so it can quite easily fall off when carried. Focus the lens closer and the cap fits more snugly.
Asahi Super Takumar 55mm f/2.0 Performance
With older lenses, not telecentric in design, the actual performance on digital can be quite variable, but this design has no need to make any apologies for its age. Sharpness both centrally and at the full frame edge is of a very high standard, being very good at all apertures and all over the image field. It is also worth noting that the results are very even right across, with the actual figures for centre and edge being within a whisker of being identical.
Asahi Super Takumar 55mm f/2.0 MTF Charts
How to read our MTF charts
The blue column represents readings from the centre of the picture frame at the various apertures and the green is from the edges.The scale on the left side is an indication of actual image resolution as LW/PH and is described in detail above. The taller the column, the better the lens performance.
For this review, the lens was tested on a Pentax K-1 using Imatest.
Asahi Super Takumar 55mm f/2.0 Chromatic Aberration Charts
How to read our CA charts
Chromatic aberration (CA) is the lens' inability to focus on the sensor or film all colours of visible light at the same point. Severe chromatic aberration gives a noticeable fringing or a halo effect around sharp edges within the picture. It can be cured in software.
Apochromatic lenses have special lens elements (aspheric, extra-low dispersion etc) to minimize the problem, hence they usually cost more.
For this review, the lens was tested on a Pentax K-1 using Imatest.
Distortion measures -1.07% barrel, pretty much what we would expect for a fast 50mm and a relatively modest value. Correction can be undertaken in software, but again for most subjects is unlikely to be needed.
Bokeh is a relatively new term, but the out of focus areas in images are indeed very smooth and images shot with the lens have a really good “look”.
Flare is not a problem either, whether or not the lens has conventional or multi-coating. In fact, many lenses had multiple layer coating even before Pentax launched the concept of Super Multi Coating, now abbreviated to SMC.
Asahi Super Takumar 55mm f/2.0 Sample Photos
For more options have a look at the Top 26 Best Pentax Lenses.
Asahi Super Takumar 55mm f/2.0 Verdict
A typical price for one of these lenses might be as little as £10, or perhaps up to £25. Faster options will be slightly more, but something really nice should be easily found at under £35. At these price levels, a good example is perfectly usable for critical photography and the performance is significantly better than many standard zooms. Factor in the cost of the adapter for your camera, but even so the value for money is without question. There is nothing to lose by trying these older lenses and much fun to be gained. They can easily be used for the most critical photography if desired.
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Easy to use, great results, a classic lens that is fully usable on digital DSLRs. |