Data sheet: Kowa Prominar-Miranda 50 mm f/1.9

Pekka Buttler, 06/2026

Specifications

The table below summarises the lens’ key specifications (measurements based on sample pictured above):

Brand(s):	Kowa Opt	Lens name	Prominar-Miranda 1:1.9 f=5cm
Focal length(s)1	50 mm	Angle-of-view2	46 °
Maximum Aperture	f/1.9	In Production	likely 1959–63
Lens mount (this lens)	Miranda	Mount subtype	PAD (Auto aperture through pass-through device)
Length3	44,4 mm	Diameter4	56,5 mm
Filter ring diameter	46 mm	Weight	269 grams
Lens element count	6	Lens group count	4
Aperture blades (S/R/C)5	6 S	Focus throw	290 °
Minimum focusing distance (measured)	44 cms	Maximum magnification (measured)	1:6,3
Has manual aperture ring	YES	Has Manual focus ring	YES
Aperture mechanism type	Automatic/Manual	Aperture click stops 6	1.9-2•2.8•4•6.6•8•11•16

Other notes:
• Before the introduction of the 1960 Automex, Miranda used a PAD/pod (external pass-through device) to facilitate automatic aperture.
• The documentation of the Miranda C and D cameras (launched 1959) mention a 5 cm f/1.9 lens using a pass-through arrangement for auto aperture. That lens is variously referred to as a ‘Miranda’ lens and as a “Kowa Prominar-Miranda” lens. Whether these are the same lens with different names is unclear.
• The Kowa Prominar-Miranda (this lens) was manufactured by Kowa Optical Works specifically for the Miranda cameras.
• If you want to use a lens hood with this lens, any normal lens hood using a 46 mm filter thread will work nicely.

Historical notes:
• Miranda was – in its heyday – an advanced Japanese camera manufacturer. You can read more about Miranda camera in the JAPB company profile on Miranda camera.

• Importantly, Miranda was a camera manufacturer and not a lens manufacturer. This mean that from early on, Miranda cameras came equipped with various brands of lenses, including some rather prominent manufacturers such as Kowa and Zunow.
• Lenses branded as “Miranda” or “Soligor Miranda” were not manufactured by Miranda, but were sourced from other manufacturers and branded ‘Miranda’. Most often these lenses were sourced from Miranda’s long-time partner (and later: owner) Soligor (Allied Impex Corporation). Hence, the actual manufacturer of “Miranda” lenses is most often impossible to discern with certainty.

Versions/variants

The table below summarises the development of Miranda 50 mm f/1.9 and f/1.8 lenses. (Underlined data is based on measurements, other data is based on Miranda documentation.)
For more information on generations of Miranda lenses, see the Miranda lens compendium.

Mainline spec	Years	Generation	Recipe	MFD	Filter	Length	Diameter	Weight	Notes
50 mm f/1.9	1959–60	PAD	unknown	0,45 m	unknown	unknown	unknown	unknown
50 mm f/1.9	1959–63	PAD	6e / 4g	0,44 m	46 mm	44 mm	57 mm	269 g	(this lens)
50 mm f/1.9	1960–70	MEX-REX	6e / 4g	0,48 m	46 mm	41 mm	58 mm	192 g	[data sheet] also ‘Soligor Miranda’
50 mm f/1.9	1963–68	F-G-MAT	6e / 4g	0,43 m	46 mm	42 mm	58 mm	193 g	[data sheet]
50 mm f/1.8	1970–74	MEX-REX	6e / 4g	0,43 m	46 mm	47 mm	59 mm	235 g
50 mm f/1.8	1968–74	F-G-MAT	6e / 4g	0,43 m	46 mm	42 mm	59 mm	203 g	[data sheet]
50 mm f/1.8	1972–74	E	6e / 4g	0,45 m	52 mm	44 mm	59 mm	228 g	[data sheet]
50 mm f/1.8	1974–76	EC	6e / 4g	0,43 m	49 mm	43 mm	60 mm	218 g	[data sheet]
50 mm f/1.8	1974–76	DUAL	6e / 4g	0,43 m	52 mm	51 mm	unknown	226 g

Adapting

This lens cannot be used natively on any current SLR or dSLRs. To use it in its native environment, you will need a Miranda Camera film body. While this lens will mount on any Miranda camera that uses the Miranda mount, its automatic aperture stop-down will work only on Miranda bodies after the Miranda F (launched 1963). For the aperture communication arm to be able to communicate aperture values, this lens needs to be mounted on an Automex or Sensorex series body.

Thanks to being a fully manual lens (manual aperture, manual focus), the lens can be adapted to all mirrorless cameras using a suitable adapter. However, Miranda adapters are not as easily available as adapters for many other legacy era camera mounts, nor is there a wide variety of specialist adapters.

Using Miranda lenses on dSLRs is a theoretical possibility. Thanks to the relatively short flange focal distance of the Miranda mount (at 41,5 mm, clearly shorter than that of any full-frame dSLR mount), any adapter will necessitate some corrective optics to achieve infinity focus.

Footnotes

1. Focal length is (unless stated otherwise) given in absolute terms, and not in Full-frame equivalent. 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 its shortest. ↩︎
4. Diameter excludes protrusions such as rabbit ears or stop-down levers. ↩︎
5. S=straight; R=rounded; C=(almost)circular at all apertures. ↩︎
6. Numbers equal aperture values on aperture ring; • intermediate click; – no intermediate click. ↩︎