Data sheet: MIR-38B 65 mm f/3.5 (Pentacon 6)

Pekka Buttler, 02/2024

Specifications

The table below summarizes the lens’ key specifications (measurements based on pictured lens):

Brand:	MIR/MИP	Lens name	38B/38Б 3.5/65
Focal length(s) 1	65 mm	Angle-of-view 2	66 ° (on medium format) ≈35 ° (on ‘full frame’)
Maximum Aperture	f/3.5	In Production	1978–≈1993 (all variants) 1978–1979 (this version)
Lens mount (this lens]	Pentacon 6	Other lens mounts:	Kiev 88
Length 3	68,2 mm	Diameter 4	75,2 mm
Filter ring diameter	72 mm	Weight	566 grams
Lens element count	6	Lens group count	5
Aperture blades (S/R/C) 5	6 S 6	Focus throw	240 °
Minimum focusing distance	50 cms	Maximum magnification	1:5,5
Has manual aperture ring	YES	Has Manual focus ring	YES
Aperture mechanism type	Automatic	Aperture click stops 6	3.5-4-5.6-8-11-16-22

Further notes:
• The MIR-38B/V is a medium format (film) lens, meaning that its image circle is designed to cover at least 54×54 mm (what is typically referred to as 6-by-6).
• The MIR-38 was produced for two mounts:
• The MИP-38Б (translates to MIR-36B) was offered for the Pentacon Six mount, while
• the MИP-38В (translates to MIR-38V) was offered for the Kiev-88 mount.
• For all those who are not comfortable with Cyrillic:
• the Cyrillic letter Б equals the Latin letter B, while
• the Cyrillic letter B equals the Latin letter V, easy as π, eh?
• Optically these two lenses are identical. Due to the differences in mounts and flange focal distances, the rear-ends of Pentacon Six and Kiev-88 variants look slightly different, this even extends to aperture rings being slightly different.
• The MIR-38 design was introduced to replace the earlier MIR-3 design (also a 65 mm f/3.5).
• Both the MIR-38 and MIR-3 are sometimes referred to as “Flektogon copy”. This is correct only inasmuch as they (and almost any wide-angle lens) are derivatives of the retrofocus design introduced almost simultaneously in the Angenieux Retrofocus and Carl Zeiss Jena Flektogon. However, there never was a Flektogon that combined a 65 mm focal length with an f/3.5 maximum aperture (the 65 mm Carl Zeiss Jena Flektogon for Pentacon Six had a maximum aperture of f/2.8 and while it did also use a six elements in five groups design, the lens elements differ somewhat).
• All production versions of the MIR-38 were manufactured at the Arsenal plant in Kiev (modern day Ukraine).
• The pictured sample (serial 786006) is an early sample, from the first year of production. In fact, it is the lowest serial number among 50+ I have seen by scouring eBay and other forums. If you have an even earlier serial number, be in touch.
• The MIR-name does not refer to a brand, design bureau or indeed a factory. Instead, the name MIR indicates that it is a retrofocus design. See more in the JAPB articles on Soviet lenses and the Soviet lens ‘business’

Versions

Based on a thorough analysis of 50+ copies on eBay and other similar sites, there are not only versions for the two medium format mounts (Pentacon Six and Kiev-88), but also three visually distinct versions.

Version 1 (1978–1979)

As pictured, all-metal construction with focus ring that is scalloped with lengthwise grip ridges. The serial number range of this version I have found is 786006 [my copy] to 794003.

Version 2 (1979–1990)

Otherwise similar, but the focus ring has changed from the pictured to a quadratic, knurled surface (see example here). The serial number range found is 795262–902532.

Version 3 (1991–1993)

Total housing redesign. Rubber focus ring with pronounced ridges on focus ring. Focus distance setting is in a ‘window’ (Takumar-style). Depth of field markings are coloured. Only two samples encountered, one of which has depth of field-markings in green, the other in red.

Interestingly, the first versions (until about 1980) of the MIR-38 also had copper-coloured aperture blades. Thereafter the aperture blades are silvery.

Adapting

If you’ve come into possession of this lens, your sample will either have a Pentacon 6 mount, or a Kiev-88 mount. Here I will discuss adapting the lens in Pentacon 6 mount, but the same principles apply to a lens with the Kiev-88 mount.

To use this lens natively, you will need a Pentacon 6 mount film body. In practical terms this means either a Praktisix or Pentacon Six medium format film camera or a Kiev 60/6C medium format film camera. While neither of these families of bodies were manufactured in their millions, they remain readily available, and even serviceable.

Thanks to the generous image circle Pentacon 6 lenses offer, and thanks to the copious flange focal distance (74,1 mm) of the Pentacon 6 system, this lens can be adapted to every full frame (and smaller) SLR, dSLR and mirrorless camera assuming a suitable adapter can be found or manufactured. Moreover, Pentacon 6 lenses are so uncomplicated that a simple ‘dumb adapter’ will do the job perfectly.

Thanks to the generous image circle, Pentacon 6 lenses have also long been a strong candidate to be used on smaller formats (full frame and smaller) in conjunction with tilt/shift adapters. Alternatively, one can choose to daisy-chain adapters (e.g. Pentacon 6->Canon EF; Canon EF –> mirrorless) which not only broadens the range of available adapters, but also allows using speed boosters for those photographers that use smaller than full-frame sensors.

Finally, regarding larger than full frame, there are also options. Digital medium format is perfectly usable (assuming adapter availability) and many 6×4,5 film formats are likewise theoretical possibilities, but gaining functional adapters may necessitate some DIY.

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 (based on manufacturers’ specs) 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. ↩︎
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. ↩︎