Pekka Buttler, 02/2024
Specifications
The table below summarises the lens’ key specifications (measurements based on pictured sample):
| Brand: | Chinon | Lens name | Auto Multi-coated 1:1.4 f=50mm |
| Focal length(s)1 | 50 mm | Angle-of-view2 | 46,8 ° |
| Maximum Aperture | f/1.4 | In Production | ≈1975–1985 |
| Lens mount | Pentax K | Subfamily (if applicable) | K-type (see details) |
| Length3 | 39,1 mm | Diameter4 | 60,9 mm |
| Filter ring diameter | 49 mm | Weight | 245 grams |
| Lens element count | ? | Lens group count | ? |
| Aperture blades (S/R/C)5 | 6 S | Focus throw | 210 ° |
| Minimum focusing distance | 45 cm | Maximum magnification | 1:6,9 |
| Has manual aperture ring | YES | Has Manual focus ring | YES |
Further notes:
• This lens was Chinon’s fast fifty during the period when its SLR cameras used the Pentax K mount.
• I have been unable to find trustworthy details on production dates, but Chinon quickly saddled over to the Pentax K mount after its introduction (1975) and largely lost its ambition in manufacturing SLRs after Minolta’s introduction of autofocus (1985). The actual production run might be significantly shorter.
• Somewhere in the production run of this lens, Chinon made a cosmetic change and changed the typography and colouring of the lens’ name ring: One version is as pictured above, another
• Chinon is not known for having manufactured the lenses it sold under the Chinon brand. Hence, the lens likely originates with a Japanese OEM manufacturer (Cosina is a relatively strong bet).
• Problematically, there is little hard knowledge about the lens’ optical design (elements & groups), compounded by the confusion caused by that the same lens also was sold as Auto Revuenon 50 mm f/1.4 [data sheet] and Agfa Color Multi-Coated 50 mm f/1.4 (see on Flickr) (and that there are two distinct versions of both the Auto Revuenon and Agfa Colot, with different barrel designs, different numbers of aperture blades, and – reportedly – different optical designs. Summarising the various online accounts, this lens either has a 7 elements in 6 groups design or a 6 elements in 5 element design (if I ever have cause to open this lens up and count the elements, I’ll update this data sheet). If you’re interested the convoluted versions of this lens, head to the data sheet of the Revuenon sibling.
A brief history of Chinon
Chinon is known to still photographers as one of the more advanced 2nd tier Japanese cameramakers. What might surprise still photographers is that Chinon was actually more strongly involved with motion picture photography and that this was a field within which Chinon managed to put in some industry ‘firsts’ (such as being the first Japanese company to produce a 8mm motion picture camera to record picture and sound simultaneously).
Chinon Industries Inc. (originally Sanshin Seisakusho) was founded in 1948 by Chino Hiroshi in the city of Chino (Nagano prefecture), originally as a subcontractor to the optics industry. In 1956 the company began manufacturing 8 mm motion picture cameras and in 1956 Chinon developed and manufactured the first zoom lens for an 8 mm camera.
In the late 1960s, likely inspired by the success other Japanese optical companies were having, Chinon started manufacturing SLRs. The first years saw relatively run-of-the-mill SLR bodies (m42 mount, stop-down metering), but Chinon soon climbed up the market ladder, and by ≈1973 Chinon was producing m42 mount SLR bodies with advanced features such as auto-exposure (on an m42 body (!)).
After Pentax abandoned the m42 mount in 1975 for their proprietary Pentax K bayonet mount, Chinon (among other Japanese 2nd tier manufacturers) followed suit. Chinon’s innovation trajectory reached its apex (other may say: its nadir) its the introduction of the Chinon CE-5 – a camera that enabled you to use Chinon’s patented infrared autofocus system (on select lenses) (see some more details in the JAPB article on autofocus).
After Minolta’s 1985 introduction of their autofocus SLR (coupled with the somewhat lacklustre response to Chinon’s introduction of their take on AF ≈3 years earlier), Chinon either lost its mojo or decided that competing with Minolta (and Canon, and Nikon, and Pentax, and Olympus, and …) was not where they wanted to spend their energy. As a result, Chinon instead silently withdrew from SLR manufacture and instead focused on point&shoots as well as the Chinon Genesis series (which could be argued to be some of the first exemplars of what we today call ‘bridge cameras’).
During the 1990s the name ‘Chinon’ disappears from store windows, but the company does not go under. Instead it first focuses on being an OEM manufacturer and has a strong, early role as OEM manufacturer of digital cameras. Later Chinon is acquired by Kodak Japan Limited.
Interestingly, for all its emphasis on designing and manufacturing technologically advanced SLRs, and earlier involvement with 8 mm lens development, Chinon did not produce its own 35 mm lenses. Instead, concerning lenses, Chinon acted as if they were a pure rebranded, and sourced its lenses from other Japanese OEM manufacturers. While one cannot often say anything precise about the origins of lenses sourced from Japanese OEM’s this lens is a bit special, as it hails from the hallowed dojo at Tomioka.
Adapting
If you want to natively mount this lens you need to find a functioning Pentax K mount SLR (or a dSLR) camera. Luckily that should be relatively easy as Pentax K film bodies were produced in their millions and most of them – especially those manufactured by Pentax – have a good reliability record. Alternatively, you can use this lens natively on any Pentax dSLR.
Adapting this lens to a mirrorless, full-frame digital camera is a breeze thanks to the lens having full manual controls (aperture ring, focus ring). You simply need a dumb adapter from Pentax K to your mirrorless system.
Due to the medium flange focal distance used by the m42 mount (45,46 mm), whether you can adapt this lens to other than Pentax’ dSLR mounts depends on which dSLR mount: Canon EF, and Four Thirds can mount Pentax K lenses using a simple adapter ring. Minolta/Sony A and Nikon F on the other hand are not as problem-free, and – to retain anything near infinity focus – the adapter will necessitate corrective optics. In all cases, your camera will work only in stop-down metering.
Footnotes
1 Focal length is (unless stated otherwise) given in absolute terms (not in Full-frame equivalent), and according to the manufacturer’s naming practice (which does not always reflect the lens’ actual field of view). For an understanding of whether the lens is wide/tele, see ‘Angle-of-view’.
2 Picture angle is given in degrees and concerns the diagonal picture angle. Rule of thumb:
> 90 ° ==> Ultra-wide-angle
70–90 ° ==> Wide-angle
50–70 ° ==> Moderate wide-angle
40–50 ° ==> ‘Standard’ or ‘normal’ lens
20–40 ° ==> Short tele lens
10-20 ° ==> Tele lens
5-10 ° ==> Long tele lens
< 5 ° ==> Ultra-tele lens
3 Length is given from the mount flange to the front of lens at infinity. Measured unless stated otherwise.
4 Diameter excludes protrusions such as rabbit ears or stop-down levers. Measured unless stated otherwise.
5 S=straight; R=rounded; C=(almost)circular at all apertures.