Asahi Optical Co., Ltd. was founded by Kumao Kajiwara in 1919 in Japan and became one of the leading manufacturers of photo cameras and lenses. The production of photo lenses started in 1931 but the true success came to Asahi only in 1951 when Asahiflex — first Japanese 35 mm SLR camera — came out. First Takumar lenses for Asahiflex camera had M37 thread mount, after some time the M37 thread was replaced by M42 and the lenses with M42 mount were produced till 1975 when threaded mount was abandoned due to release of the new Pentax system based on K bayonet mount.
The Asahi Takumar 1:2.5/135 is a full-frame manual portrait prime which exists in several incarnations:
- Super-Takumar (1968-1971) – has early type of coating, allows to select manual or automatic aperture mode by a special switch on the housing. Optically it’s based on 5 elements in 4 groups, has 6 aperture blades, weighs 444 g, has 58 mm filter thread;
- Super-Multi-Coated (1971-1972) — multicoated, allows metering without preliminary closing the diaphragm to shooting aperture. Other characteristics are the same of Super-Takumar’s;
- Super-Multi-Coated (1973-1979) – optically consists of 6 elements in 6 groups, has 8 aperture blades, weighs 470 g. The rest of the characteristics were unchanged;
- smc Pentax (1975-1985) – has Pentax K bayonet mount, but optically identical to Super-Multi-Coated (1973-1979).
In 1980-90s the Pentax Corporation «resurrected» Takumar brand for the series of single-coated budget lenses. Such lenses were marked as Takumar (Bayonet) to distinguish them from the old threaded ones. Pentax did produce Takumar 1:2.5/135 Bayonet, but optically it was different and consisted of 4 elements in 4 groups. Other characteristics are also different from the classic version: automatic aperture is missing, the minimal focus distance is 1.2 m, the filter thread is 52 mm, the lens has built-in hood. In fact, it’s quite a different design and there are no reasons to consider it as a «continuation» of the base model, despite the focal length of 135 mm and a maximum aperture of F/2.5.
It is worth noting that there are not so many full-frame portrait primes with a focal length of 135 mm and a maximum aperture of 2.5 because the optics with such parameters is ambitious enough per se. You could find the following alternatives to the reviewed lens:
|P. Angenieux Paris F.135 1:2.5 Type P2||Nikon F, Exakta, M42||from 2700 USD|
|EBC X-Fujinon-T 1:2.5 f=135 DM||Fujica-X||unknown|
|EBC Fujinon-T 1:2.5 f=135 DM||M42||unknown|
|Konica Hexanon AR 135mm F2.5||Konica AR||from 143 USD|
|Tamron Adaptall-2 135mm 1:2.5||Adaptall-2 interchangeable mount system||from 117 USD (from 50 USD w/o mount)|
|Canon FD 135mm 1:2.5 S.C.||Canon FD||from 50 USD|
|Canon FL 135mm 1:2.5 S.C.||Canon FL||unknown|
So, we have determined that our sample of Super-Takumar 1:2.5/135 is the earliest model in the line of Asahi M42 lenses. On a full-frame cameras it’s a portrait lens and on APS-C cameras it becomes a telephoto prime. In this review the lens was used with the Fujifilm X-Pro1 camera with a crop factor of 1.53, and the effective focal length of the lens «became» 206.5 mm (full-frame equivalent). The lens was used via M42 — Fuji X adapter without chip. There was no focus confirmation, but the metering was performed by the camera automatically in the stop-down mode. All you have to do is just to select the desired aperture and rotate the manual focus ring until you have your subject sharp in the EVF or LCD in Live View mode.
Build Quality and Characteristics
The build quality of the lens is great (in fact, this is pretty typical for the most lenses of the late 1960s) and is not comparable not only to the modern high-quality plastic lenses, but even to the all-metal Pentax Limited series of lenses. The black housing of the lens is completely made of metal, including thread mount, has a moderate for this class of lenses weight of 444 g and a length of 85 mm (when focused on the infinity; not including the caps). The noticeable weight partly helps to eliminate the image blur caused by the camera shake. You have to set the shutter speed no longer than 1/200 if you don’t want to get blurred images when shooting handheld.
The manual focus ring is wide (35 mm), well damped, has no play, rotates smoothly, but kinda tight. The condition of various control elements of the lens depends on the year of manufacture and the level of preservation of a particular lens. The angle of rotation of the ring is formally not so big (180 degrees), but actually it is pretty sufficient to provide the accurate focusing. The front element is pushed forward by 14-15 mm when focusing on the minimum distance of 1.5 m. There is a distance scale and depth of field scale of course.
The aperture ring has the following markings: 2.5 — 4 — 5.6 — 8 — 11 — 16 — 22. There are half stops between F/2.5 and F/16 but they are not indicated on the scale. The aperture works in manual and automatic modes, there is a corresponding switch on the rear part of the housing. The switch is irrelevant for today’s digital cameras.
The aperture has 6 blades, its opening is not circular, but this is not so surprising, because the production of the lenses with a circular aperture started only in 1987 by the Minolta Corporation — 12 years after withdrawal of Asahi Takumar lenses from the production. The Super-Multi-Coated Takumar (1973-1979) and newer 135/2.5 models all have 8 aperture blades.
The diameter of the filter thread is 58 mm — a common size among Asahi (Pentax) lenses. The filter thread does not rotate when focusing, making it easy to use polarizing and gradient filters. No filters were used during shooting for this review.
The buyers of this lens used to get both caps, hard case and a big metal threaded hood which has height of 54 mm and is also suitable for the Asahi Takumar 1:4/200 lens (which is clearly stated on the hood itself).
Optically the lens consists of 5 elements in 4 groups. The Super-Multi-Coated Takumar (1973-1979) and smc Pentax-K (1975-1985) consist of 6 elements in 6 groups and the multicoating is more advanced which teoretically result in greater resistance to flares and ghosting and better overall contrast of the images.
The optical elements of the reviewed lens have no any noticeable yellow cast (a common characteristic of many Asahi Super-Takumar lenses).
The lens exhibits very good sharpness in the center of the frame already from F/2.5. With closing of the aperture the sharpness increases rapidly and is great from F/5.6. The overall contrast remains excellent and unchanged on every aperture. The quality of edges of the frame with X-Pro1 APS-C sensor are visually not far behind from the center of the frame.
The depth of field at F/2.5 is narrow even on APS-C sensor and if you want, you could achieve truly impressive separation of the main subject from the background.
Vignetting is not noticeable with APS-C sensor, the same goes to distortion and lateral chromatic aberration.
The quality of the bokeh is very good. The background blur in most cases is very smooth and soft and achieved easily (thanks to large focal length and fast aperture of the lens). The degree of blurring, however, also depends on the distance between the front element of the lens and the subject, the distance between the subject and the background.
The out-of-focus highlights are round and evenly rendered at F/2.5, but become hexagons starting from F/4. It’s a bit disappointing considering the overall magnificent lens optical results.
Longitudinal chromatic aberration (colored halos in front of the focus point and in the background) of this lens could be called strong. At F/2.5-4 the aberration is clearly visible on contrast transitions, water droplets, shiny metal surfaces, etc. The effect is significantly reduced from F/5.6 and no longer affects the image quality from F/8.
The Asahi Super-Takumar 1:2.5/135 is a gorgeous fast telephoto lens when used on APS-C cameras. Mechanically it does not leave much to be desired — the lens is ergonomic, easy to use and optically competes with modern autofocus lenses designed for use with demanding digital sensors. The sharpness of the whole APS-C frame is very good already from F/2.5 and excellent on the subsequent apertures and the only visible optical aberration is longitudional CA. The background blur is very smooth and soft and could be achieved without much effort from the photographer (just set F/2.5 and move far enought from your subject). The only thing, perhaps, that you can blame the lens for is a bokeh hexagons from F/4 onwards.
Author of the review and photos: Evgeny Artemov, firstname.lastname@example.org