Data sheet: Meyer-Optik Görlitz Orestegor (300 mm f/4)

Pekka Buttler, 11/2024

Specifications

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

Brand:	Meyer-Optik Görlitz	Lens name	Orestegor 4/300
Focal length(s) 1	300 mm	Angle-of-view 2
Maximum Aperture	f/4	In Production	1967–1970 (Meyer-Optik Orestegon) 1967–1990 (All versions)
Lens mount (this lens)	M42	Other lens mounts	Exakta (outer), Praktina, Pentacon Six
Length 3	245 mm	Diameter 4	99,9 mm
Filter ring diameter	95 mm	Weight	1977 grams (without lens hood or mount adapter) 2100 grams (with M42 mount adapter and lens hood)
Lens element count	5	Lens group count	4
Aperture blades (S/R/C) 5	19 S	Focus throw	330 °
Minimum focusing distance	3,6 m	Maximum magnification	1:9:9
Has manual aperture ring	YES	Has Manual focus ring	YES
Aperture mechanism type	Preset	Aperture click stops	None (clickless)

Further notes:
• The name Orestegor identifies the lens as one of MOG’s later series (all MOG lenses post-1963 are named Orest-something) of long focal length lenses (everything beyond 200 mm was named Orestegor, even though the optical designs of the 200 mm, 300 mm, and 500 mm differed).

• The 300 mm f/4 Orestegor was introduced to replace the 300 mm f/4.5 Telemegor, which in turn replaced the 250 mm f/5.5 Telemegor [data sheet] and the 400 mm f/5.5 Telemegor
• This 300 mm Orestegor has an integrated tripod mount that can be rotated and locked in 0–360 °.
• After the 1970 shotgun merger with VEB Pentacon, this exakt same lens was sold for 20 more years as the Pentacon 300 mm f/4⁶
• All versions of the Meyer-Optik / Pentacon 300 m f/4 lens are preset aperture lenses with 19 aperture blades.

• The Meyer-Optik Orestegor 300 mm f/4 came with a short (27 mm) lens hood that most people have permanently left on the lens. However, to access the 95 mm (non-rotating) filter threads, that lens hood has to be temporarily removed.

• Alike many tele lenses designed in the 1960s by Meyer-Optik Görlitz, the Pentacon 300/4 used Meyer-Optik’s proprietary interchangeable mount system, and was therefore theoretically usable on a wide range of cameras:
– the initial Meyer-Optik Orestegon 300/4 as well as the early Pentacon 300/4 lenses could be purchased with a mount for either Exakta (outer bayonet), M42, Pentacon Six or Praktina mount cameras
– from roughly the early 80s, the lens was also offered with mounts for the Praktica B mount.
– because the interchangeable mount parts are relatively simple, any competent machinist is able to produce a mount for any full frame (or smaller) camera mounts, while some medium format (film mounts) are impractical due to adverse flange focal distance differences.
• While the name Orestegor covers 200, 300 and 500 mm focal lengths, the 300 and 500 mm designs are in many ways related and do also share the interchangeable mount system (mount adapters for the 300 mm could be used on the 500 mm and vice versa.
• This lens is something of an oddity, because it seems it was designed to serve both the 35 mm / ‘full-frame’ (Praktina/Exakta/Praktica) but also Medium Format (Praktisix/Pentacon Six) cameras. The requirement for being able to comfortably cover medium format film (≈80 mm diagonally) has been defining for the designing of the lens. Hence, for use on full-frame or 35 mm film, the lens is somewhat over engineered and enjoys a sweet-spot advantage.
• For further notes on Meyer-Optik Görlitz and especially their naming logic, see the JAPB article on MOGnames (the company’s later history is summarised below).

History of Meyer-Optik Görlitz

The original Meyer-Optik Görlitz (not the modern company that has taken the classic company’s name) was founded in the town of Görlitz (modern-day Germany) by Hugo Meyer in 1896, and remained in existence until the state-directed merger into VEB Pentacon 1970. Due to its vicinity with the German camera and optics industries in Saxony (Dresden, etc.), Meyer-Optik was from an early stage heavily involved with manufacturing lenses for all kinds of cameras, but the company’s real golden age started with the advent of interchangeable lens cameras, where Meyer-Optik was uniquely placed to offer a cost-effective alternative to premium brands such as Carl Zeiss Jena.

Meyer-Optik was pronouncedly a camera lens manufacturer and never had serious ambitions for pursuing horizontal integration (diversifying into cameras and other photo gear). Instead, MOG pursued a vigorous strategy of seeking economies of scale, combined with never putting too many eggs in any basket – typically Meyer-Optik would choose which designs to put into production based on being able to cover as many platforms/mounts with one basic design. As a result, many early MOG designs were made available for a wide range of camera platforms. Later, as the number of alternative platforms diminished, that strategy had to go in favour of a strong focus on M42 and (to a somewhat lesser extent) Exakta. Even so, throughout the 60s, MOG vigorously pursued innovative designs and could by the end of the decade proudly offer a wide range of high-quality, cost effective designs.

When the lens maker Meyer-Optik was then merged with the camera maker Pentacon, it became obvious that the role the company (and its product portfolio) was intended to play was to aid Pentacon in its designs of gaining a significant global market share in the price-conscious consumer segment (and help bring hard currency to the G.D.R). Instead of focusing on continued optical innovation, the new overlords were more keen on redesigning lenses for greater economy and easier manufacture. As a result, the pace of optical innovation at MOG/Pentacon fell drastically, and very few new designs or significant redesigns were to be forthcoming in the next two decades.

Versions

There is only one cosmetic variant of the Meyer-Optik Orestegor 300/4.

However the Pentacon 300/4 was produced in two cosmetically different but optically identical variants: an earlier variant that has similar control surfaces as the earlier Meyer-Optik Orestegor and a later variant that offers a quadratic patterning on the (metal) focus ring.

The Meyer/Pentacon 300/4 stayed in production all the way past German reunification.

Adapting

(Here we will discuss adapting this lens on the assumption that you have a version sporting the M42 mount piece. If you have another mount, look up the JAPB article on that mount)

This lens cannot be used natively on any current SLR or dSLRs. To use it in its native environment, you will need an m42-mount film body. Luckily there are a lot of those available and in working order.

Thanks to being a fully manual lens (manual aperture, manual focus), the lens can be adapted to all mirrorless cameras using a suitable adapter. Moreover, m42 lenses are so uncomplicated that a simple ‘dumb adapter’ will do the job perfectly. Further, due to the popularity of the m42 mount, special adapters (helicoid adapters, tilt/shift adapters) are readily available. Alternatively, one can choose to daisy-chain adapters (e.g. m42->Canon EF; Canon EF –> mirrorless) which also opens up a wide range of speed boosters .

Using m42 lenses on dSLRs can also be an easy option, depending on which dSLR.
• Canon EF has the shortest flange focal distance among full-frame dSLR’s and Canon’s wide range of dSLRs are able to mount m42 lenses perfectly, using a simple adapter ring.
• Minolta / Sony A dSLRs and Pentax dSLRs are likewise able to mount m42 lenses using a simple adapter ring.
• Nikon F dSLRs have a long flange focal distance, meaning that mounting M42 lenses needs an adapter that uses corrective optics to allow anything close to 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 (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. There are some brochures (from just after the Meyer-Optik–Pentacon merger) that mention this lens as the Pentaconar 300 mm f/4 lens, but I have never observed a copy in the wild. It might be that Pentacon abandoned all plans regarding the ‘Pentaconar’ name before the existing stock of Meyer-Optik 300/4 lenses was exhausted, ↩︎