Asahi Super Takumar 50mm f/1.4 Review

John Riley reviews the Asahi Pentax Super-Takumar 50mm f/1.4 Model I (8-Element), and finds out if the lens deserves the legendary status it has.

01/06/2018 - 08:43

Handling and Features
Performance
Verdict
Specification

Some lenses do gain a legendary status, and the Model I Super-Takumar 50mm f/1.4 is one of them. The first claim to fame is the use of radioactive Thorium glass, the second is that this first model of 8 elements was soon replaced by a 7 element version and the Model I became the stuff of legends for its extraordinary performance. Manufactured from 1964-1965 we can now have a close look to see how it performs using the Pentax K-1 DSLR. Will the 36MP digital images have that same magic about them? Let's find out.

Asahi Super-Takumar 50mm f/1.4 Model I Handling and Features

Introduced along with the then-new Pentax Spotmatic, this lens has a small caveat attached to its use on early film cameras. It can only be used on pre-Spotmatic S1a/H1a and SV/H3v film bodies that have the new crescent shaped push plate to activate the stop down pin. The appropriate cameras will usually have a 7-digit serial number and an orange R on the rewind crank. This is because the rear element protrudes and can foul the mechanism of earlier film bodies. Having baffled us DSLR users though, we need have no such fears as our cameras have moved on somewhat.

The screw thread lens mount is devoid of electronic contacts and an adapter is needed to fit the lens to our selected DSLR 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.

Having mounted the lens, our brief tour starts at the large front element and the 49mm filter thread. Whereas the push on metal lens cap can be partially pushed off when some of the smaller aperture lenses are used, the f/1.4 version has no such problem.

The focusing ring is sculpted for grip, and the sheer pleasure of operating the focusing mechanism brings new meaning to the phrase silky smooth. This particular sample has not worn totally evenly, having a stiffer section in its travel, but the point holds good for most of these lenses. 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/11. The stop to the widest, f/1.4, and smallest, f/16, apertures is a full stop, with no half stop indent. Behind this is the Auto/Manual switch which selects between 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. In this case the lens is early enough to have no additional levers on the mount, so use is perfectly straightforward.

The optical construction is 8 elements in 7 groups. Focusing is down to a conventional 0.45m or 1.5 feet and the lens weighs in at 245g.

In the context of 1964, handling of the Super-Takumar lenses is sublime. They focus closer than many, have super-smooth controls, are compact and have an elegance of design that makes many contemporaries look very clunky in comparison. In the context of 2018 and a DSLR, manual focus is what it is and will suit some and not others, but otherwise the lens is still quite beautiful to use. There is a certain pleasure to be experienced in such elegance of engineering, design and fine quality of manufacture.

Asahi Super-Takumar 50mm f/1.4 Model I Performance

In 1964, the design ethos of an f/1.4 lens was somewhat different to today. As a consequence, we might expect that wide open the lens may not be razor sharp, but it will be when stopped down. Using Imatest, sharpness centrally is simply very good all the way through the apertures. The edges are also very good and virtually matching the centre from f/2.8 to f/16. However, at f/1.4 the edges are ethereally soft and likewise at f/2, although gradually sharpening. Critical sharpness clicks in at f/2.8. This means that we have the possibility of some truly wonderful bokeh effects at the two widest apertures, and does bear out the reputation of the lens as being something special in a creative sense. Portrait photographers might see huge benefits in this design choice.

Pentax Super Takumar 50mm f/1.4 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.

 

CA (Chromatic Aberration) is very well controlled, almost banished centrally and still kept to very low values at the edge. One of the minor surprises of doing these vintage reviews is finding that CA was much better corrected for than anticipated.

Pentax Super Takumar 50mm f/1.4 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 -1.52% barrel, a very good result and not likely to be a problem.

Bokeh is very, very smooth and here the qualities of the lens shine through. We end up with a lens that indeed produces a “look”, a delightfully vague term but one that can be very easily understood when the results are seen.

The conventional coating does mean that use of a lens hood is advisable, as flare can intrude on images unless care is taken. It is, however, no worse than any other quality lens of the period and does not prevent the making of some great images.

Pentax Super Takumar 50mm f/1.4 Sample Photos

 

Pentax Super Takumar 50mm f/1.4 Aperture range

 

 

 

Asahi Super-Takumar 50mm f/1.4 Model I Verdict

If one of these can be found, its status and reputation unfortunately means that the price will be higher. It may also be inflated by the collectors market. What a fair price would be is something for debate, but if a good sample can be found at a price that seems acceptable to the buyer, then it will be an excellent lens to own. And, hopefully, to use.

Does it have a special quality? Yes, it probably does. There needs to be a longer period to explore the possibilities, but in this short review period the lens has certainly delivered. Without doubt there will be a pang of regret when it has to go back, which does indicate that this journey of discovery was worth the effort.

Own this lens? Let us know what you think of it in the EQDB. 

Spotted a mistake? Let us know in the EQDB.

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