Review of SMC PENTAX 1:1.8/55 ASAHI OPT. CO., JAPAN (1975-1977)

According provided by lens SMC PENTAX 1:1.8/55 ASAHI OPT. CO., JAPAN (model 20747) many thanks to the store FOCUSFILM (subscribe to INSTAGRAM, check out olx). There you can find many interesting film cameras and manual lenses.

In short

SMC PENTAX 1:1.8/55 ASAHI OPT. CO., JAPAN - a manual prime from the film era for the Pentax K mount. There is a whole family of similar lenses TAKUMAR/PENTAX class 55 / 1.8, which has approximately 5 main models.

This SMC PENTAX 1:1.8/55 ASAHI OPT. CO., JAPAN is the only model TAKUMAR/PENTAX lenses class 55/1.8 for the Pentax K mount. All previous 55/1.8 models were called TAKUMAR and used an M42 mounting thread.

All lenses TAKUMAR/PENTAX class 55/1.8 use the same optical design, which includes 6 elements in 5 groups.

SMC PENTAX 1:1.8/55 ASAHI OPT. CO., JAPAN is the latest in its line. Further TAKUMAR/PENTAX lenses class 55/1.8 were replaced by class 50/1.7. Overall old TAKUMAR/PENTAX class 55/1.8 are valued more than the subsequent 50/1.7. It is believed that versions 55/1.8 have a more “plastic” pattern and a better case design.

All major versions of similar lenses Asahi Opt. Co., Takumar / Pentax:

1.2/50

1. SMC PENTAX 1: 1.2 / 50 ASAHI OPT. CO., JAPAN (7/6, 20947, 1975-1984)
2. SMC PENTAX 1:1.2/50 ASAHI OPT. CO.,JAPAN'GOLD' (7/6, 1981)
3. SMC PENTAX-A 1: 1.2 50mm (7/6, 20987, 1984-2004)
4. SMC PENTAX-A 1: 1.2 50mm Special (7/6, 2000)

1.4 / 50 (video)

1. Super takumar 1: 1.4 / 50 Asahi Opt. Co., Lens made in Japan (8/6, 358, 1964-1966)
2. Super takumar 1: 1.4 / 50 Asahi Opt. Co. Lens made in japan (7/6, 37800, 1965-1971, F/2 in number)
3. Super takumar 1: 1.4 / 50 Asahi Opt. Co. Lens made in japan (7/6, 37801, 1965-1971, F/2 dot)
4. Super takumar 1: 1.4 / 50 Asahi Opt. Co., Lens made in Japan (7/6, 37802, 1965-1971, comma after 'CO.')
5. Super-Multi Coated TAKUMAR 1: 1.4 / 50 ASAHI OPT. CO., JAPAN (7/6, 37902, 1971-1972)
6. SMC TAKUMAR 1: 1.4 / 50 ASAHI OPT. CO., JAPAN (7/6, 37908, 1972-1975)
7. SMC PENTAX 1: 1.4 / 50 ASAHI OPT. CO., JAPAN (7/6, 20847, 1975-1977)
8. SMC PENTAX-M 1: 1.4 50mm ASAHI OPT. CO., JAPAN (7/6, 20867, 1977-1984)
9. SMC PENTAX-A 1: 1.4 50mm (7/6, 20887, 1984-1989)
10. SMC PENTAX-F 1: 1.4 50mm (7/6, 20827, 1987-1991)
11. SMC PENTAX-FA 1: 1.4 50mm (7/6, 20817, 1991-2023)
12. HD PENTAX-D FA * 1: 1.4 50mm SDMAW (15/9, 21260, 2018->)
13. SMC PENTAX-FA 1: 1.4 50mm Classic (7/6, 2023->)
14. HD PENTAX-FA 1: 1.4 50mm (7/6, 2023->)

1.8 / 55 (video)

1. takumar 1:1.8 f=55mm Asahi OPT. CO., Japan (6/5, 1958, zebra)
2. Auto-takumar 1:1.8 f=55mm Asahi OPT. CO., Japan (6/5, 1958-1960, zebra)
3. Auto-takumar 1:1.8/55 ASAHI OPT. CO., Lens made in Japan (6/5, 1960, with 'R')
4. Auto-takumar 1:1.8/55 ASAHI OPT. CO., Lens made in Japan (6/5, 1960-1962, no 'R', oblique lines of the depth of field)
5. Auto-takumar 1:1.8/55 ASAHI OPT. CO., Lens made in Japan (6/5, 1962, no 'R', straight lines of depth of field)
6. Super takumar 1: 1.8 / 55 Asahi Opt. Co., Lens made in Japan (6/5, 1962, fine ribs, f/1.8 left)
7. Super takumar 1: 1.8 / 55 Asahi Opt. Co., Lens made in Japan (6/5, before 1965, fine ribs, f/1.8 right)
8. Super takumar 1: 1.8 / 55 Asahi Opt. Co. Lens made in japan (6/5, 37106, before 1971, large ribs)
9. Super-Multi Coated TAKUMAR 1: 1.8 / 55 ASAHI OPT. CO., JAPAN (6/5, 37104, 1971-1972)
10. SMC TAKUMAR 1: 1.8 / 55 ASAHI OPT. CO., JAPAN (6/5, 37108, 1972-1975)
11. SMC PENTAX 1: 1.8 / 55 ASAHI OPT. CO., JAPAN (6/5, 20747, 1975-1977)

2 / 55 (1.9 / 55)

1. Auto-takumar 1:1.9 f=55mm Asahi Opt. Co.,Japan (6/5, 1958-1959)
2. Auto-takumar 1: 2 f = 55mm Asahi Opt. Co., Japan (6/5, 1958-1959, zebra)
3. Auto-takumar 1: 2 f = 55mm Asahi Opt. Co., Japan (6/5, 34100, 1958-1959)
4. Super takumar 1: 2 / 55 Asahi Opt. Co., Lens made in Japan (6/5, small fins, F/2 left)
5. Super takumar 1: 2 / 55 Asahi Opt. Co., Lens made in Japan (6/5, small ribs, F/2 on the right)
6. Super takumar 1: 2 / 55 Asahi Opt. Co. Lens made in japan (6/5, 37103, 1962-1973, large ribs)
7. Super takumar 1: 2 / 55 Asahi Opt. Co. Lens made in japan (6/5, 37107, additional aperture pins)
8. SMC TAKUMAR 1: 2 / 55 ASAHI OPT. CO., JAPAN (6/5, 37109, 1973-1975)
9. SMC PENTAX 1: 2 55mm ASAHI OPT. CO., JAPAN (6/5, 1976-1977)

1.7/50

1. SMC PENTAX-M 1: 1.7 50mm ASAHI OPT. CO., JAPAN (6/5, 20877, 1977-1984)
2. SMC PENTAX-A 1: 1.7 50mm (6/5, 20897, 1984-1989)
3. SMC PENTAX-F 1: 1.7 50mm (6/5, 20837, 1987-1991)
4. SMC PENTAX-FA 1: 1.7 50mm (6/5, 20907, 1991-2004)

2/50

1. SMC PENTAX-M 1:2 50mm ASAHI OPTICAL CO. (5/5, 20677, 1979-1985)
2. SMC PENTAX-A 1: 2 50mm (5/5, 20697, 1985-1998)

2.2/55

1. takumar 1:2.2/55 Asahi Opt. CO., Japan (6/5, 1961-1963)
2. Auto-takumar 1:2.2/55 ASAHI OPT. CO., Lens made in Japan (6/5, 1961-1963)

2/58

1. takumar 1:2 f=58mm Asahi Opt. Co., Japan (6/4, 1957-1958)
2. takumar 1: 2 f = 58mm Asahi Opt. Co., Japan (6/4, 1957-1958, labeled 'R')

DA (APS-C: 1.4/55 DA* + 1.8/50 DA)

1. SMC PENTAX-DA * 1: 1.4 55mm SDM (9/8, 21790, 2008->)
2. SMC PENTAX-DA 1: 1.8 50mm (6/5, 22177, 2012->)

Asahi-Kogaku (M37x1, 3.5/50 + 2.4/58 -> M42)

1. takumar 1: 3,5 f = 50mm Asahi-kogaku (4/3, 1952, M37×1)
2. takumar 1: 3.5 f = 50mm Asahi-kogaku (4/3, 1952, , M37×1, pre-set)
3. takumar 1: 2.4 f = 58mm Asahi-kogaku (5/3, 1954, M37×1, silver)
4. takumar 1: 2.4 f = 58mm Asahi Opt. Co., Japan (5/3, 1957-1958, M42)

The lens names in this list correspond exactly to the lens name label on the lens barrel (except for the serial number and/or filter diameter).

Main technical characteristics of SMC TAKUMAR 1: 1.8 / 55 ASAHI OPT. CO., JAPAN:

Review Instance Name	SMC TAKUMAR 1: 1.8 / 55 ASAHI OPT. CO., JAPAN 6841789
Basic properties	Pentax K - K mount manual focus only aperture control ring SMC (Sopera-Multi-Coated) - multi-layer optical coating lens suitable for full-frame cameras compact sizes 20747 - lens revision code
Front Filter Diameter	52 mm, metal thread for filters.
Focal length	55 mm
Zoom ratio	1 X (this is a fixed lens, it does not have a zoom).
Designed by	for film cameras with a frame size of 24 x 36
Number of aperture blades	6 petals. At an intermediate value between F/1.8 and F/4, the aperture blades form a notched hole.
Tags	focusing distance scale in meters (yellow) and feet (blue). There are marks for 10, 5, 3, 2, 1.5, 1.2, 1, 0.8, 0.7, 0.6, 0.55, 0.5, 0.45 meters and an infinity mark. And also marks 1.5, 1.75, 2, 2.5, 3, 3.5, 4, 5, 7, 10, 15, 30 feet DOF scale for f/4, 5.6 (strip only), 8, 11 (strip only), 16, 22 red label-stripe for working in the infrared spectrum white convex volumetric dot mark for convenient lens orientation red bayonet attachment point (on the side of the bayonet tabs)
Diaphragm	from F/1.8 to F/22. The lens has an aperture control ring. The ring has marks for F/1.8, 2.8, 4, 5.6, 8, 11, 16, 22. You can set one additional value between each pair of numbers (except F/16<->F/22)
MDF	0.45 meters, maximum magnification ratio 1:5.9
The weight	228 grams (measured)
Optical design	6 elements in 5 groups. The lens does not use special optical elements in its optical design. The same optical scheme is used more than early Takumar 55 / 1.8 lenses.
Lens hood	Threaded, screwed into the thread of the front filter. Original PH-R52 and PH-S52 hoods with snaps.
Manufacturer country	LENS MADE IN JAPAN (body inscription, lens made in Japan).
Period	1975-1977. Subsequently replaced by the model ASAHI OPT. CO., JAPAN SMC PENTAX-M 1: 1.7 50mm.
Price	About 100 USD for used option

Personally, I am a big connoisseur and fan of the old Pentax optics (aka TAKUMAR, aka ASAHI OPT. CO.), after working with which there are always pleasant impressions. A slightly increased focal length, compared to classic fifty-fifty lenses, on cameras with an APS-C sensor is better suited, for example, for portraiture.

Assembling, focusing

SMC PENTAX 1:1.8/55 ASAHI OPT. CO., JAPAN is well put together.

Lens bevels are poorly blackened. The aperture blades form notches in the range F/1.8-F/4. The middle part of the lens has a slightly red-purple tint. The front and rear lenses shimmer with bright colors. There is information on the Internet that some lenses have problems with the back gluing of the lenses, which causes image contrast to deteriorate.

The focus ring has an anti-slip insert made of very rough material and rotates approximately 225 degrees (5/8 of a full turn). The movement of the ring is smooth and pleasant. During focusing, the front retractable part of the housing does not rotate. Focusing occurs by moving the entire lens unit.

The aperture control ring is metal and allows you to set one intermediate value between each pair of numbers printed on this ring (except F/16<->F/22).

The lens uses a Pentax K mount and can be mounted on any modern Pentax digital SLR camera with a K mount.

Sample photos (Full Frame)

The pictures in the gallery were taken with a camera Canon EOS 5D (Full Frame, CMOS 13.3 MP) and adapter Pentax K -> Canon EF. Some of the photographs were taken using macro rings for Canon EF, since SMC PENTAX 1:1.8/55 ASAHI OPT. CO., JAPAN can catch the mirror with its long protrusions on the bayonet side Canon EOS 5D with normal adapter Pentax K -> Canon EF, macro rings remove this problem.

You can download/view source photos in RAW format (Canon '.CR2') at this link (20 files, Google Drive gallery).

Examples of photos on APS-C (Sony a3500, Nikon D40)

Camera used Sony a3500 (20 MP Sony Exmor APS-C HD CMOS sensor) with adapter FOTGA PENTAX K -> SONY E/NEX. All photographs were taken according to the principles ZEROJPEG. Also used camera Nikon D40 (sensor Sony ICX-453-AQ APS-C CCD 6 MP) with a homemade adapter.

Original photos c Sony a3500 in RAW format (Sony '.ARW) you can view / download this link (Google Drive, 25+ photos).

Appearance

The lens was in good condition for review. Next to SMC PENTAX 1:1.8/55 ASAHI OPT. CO., JAPAN shown SMC PENTAX-M 1:2.8 100mm ASAHI OPT. CO., JAPAN.

Results

SMC PENTAX 1:1.8/55 ASAHI OPT. CO., JAPAN is a bright and beautiful representative of its time. Does not have its legal heir, in the future the line of lenses TAKUMAR/PENTAX class 55/1.8 was replaced by the Pentax 50/1.7 line, the first representative of which was the lens SMC PENTAX-M 1: 1.7 50mm ASAHI OPT. CO., JAPAN.

10 main advantages

1. great build
2. convenient focus ring that rotates 225 degrees
3. standard filter diameter 52 mm
4. low cost in the secondary market
5. automatic aperture control on cameras with Pentax K mount
6. slightly increased focal length (55 vs 50 mm) for cropped sensors is more suitable for portrait photography
7. low distortion
8. nice color rendering
9. beautiful bokeh at F/1.8
10. high resolution at closed apertures

10 main disadvantages

1. Lens bevels are poorly blackened
2. only 6 aperture blades
3. the petals form notches in the range F/1.8-F/4
4. should use a screw-on hood, not a bayonet hood (the original PH-R52 and PH-S52 hoods were snap-on)
5. the middle part of the body is dark red-violet (is it supposed to be like that?)
6. non-internal focusing, without a system of floating elements
7. minor problems when working in back and side light
8. chromatic aberration (both longitudinal and transverse)
9. low resolution at F/1.8 in the corners and edges of the image
10. This is a wonderful lens, what are you talking about?

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Material prepared Arkady Shapoval. Training/Consultations | Youtube | Facebook | Instagram | Twitter | Telegram