Friedrich Deckel

(Redirected from Synchro-Compur)

Friedrich Deckel GmbH, also known as F.Deckel, was a German company founded by Friedrich Deckel and Christian Bruns in Munich as Bruns & Deckel in 1903. Its most famous product is the Compur line of leaf shutters used on many photographic lenses starting from 1911. Bruns and Deckel previously had worked together at C. A. Steinheil & Söhne; Bruns was an inventor responsible for developing leaf shutters while Deckel was a laboratory mechanic.

Zeiss Ikon folding camera equipped with a Tessar lens and a Deckel Compur rim-set shutter. Note the stylized "FD" branding on the right side of the shutter.

Corporate history

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By 1910, Zeiss had acquired a 16.8% stake in F.Deckel.[1] Zeiss also owned a significant portion of competitor Alfred Gauthier Calmbach [de] (AGC), which was later renamed Prontor after its competing leaf shutter.[1]

Taking advantage of their growing knowledge of factory production methods and machinery, by about 1920 Deckel started producing "extra" machines for sale to the trade, most notably the versatile FP line of industrial milling machines.[2] During World War II, photographic equipment production was paused and F.Deckel made fuel pumps for BMW airplane engines.[1] By the end of the war, Deckel was also said to have produced a total of some 4100 examples of their FP1 milling machine for use in the war effort.[3]

In 1958, Carl Zeiss AG purchased F.Deckel outright and in 1976 closed down the Compur factor in Munich, consolidating production with Prontor at Calmbach.[1] Leaf shutter production continued after the two companies were merged in 1984 until 2002.[4] A portion of the company, responsible for gas monitors, survives as Compur Monitors GmbH.[5] Their FP3 milling machine remained in production until the late years of the 20th Century.[6] Deckel's popular, if expensive, line of industrial tool and cutter grinders remain available for sale under the brand ISOG,[7] a division of Precision Surfacing Solutions.[8]

Leaf shutter development

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Clockwork mechanism within a Compur-Rapid leaf shutter; cocking lever at upper left and tripping lever at upper right; lever below cocking lever selects aperture.

Bruns designed Steinheil's first leaf shutter in 1899, followed by an updated version using a leather brake to control shutter speeds.[1]

While at Bruns & Deckel, Bruns developed the Compound leaf shutter in 1905, which had a pneumatic escapement for slow speeds.[1] After Bruns left the company shortly thereafter, it was renamed to F.Deckel; Bruns continued to develop shutters and replaced the pneumatic cylinder with a clockwork escapement in 1910,[9] naming the new shutter Compur as a portmanteau of Compound (from the earlier shutter design) and Uhrwerk (referring to the clockwork mechanism).[1] A consortium of photographic companies, including Carl Zeiss AG, Bausch & Lomb (25% of which was owned by Zeiss), and AGC was formed in 1910 to acquire Bruns's Compur patent, which was provided to Deckel, who produced Compur shutters under license starting in 1911.[1] Zeiss owned significant stakes in both Deckel and Gauthier.[1] The earliest shutters are marked with D.R.P. (Deutsches Reichs-Patent [de]) 258646 D.R.G.M. (Deutsche Reich Gebraumeister) for the original patent.

Leaf shutters are provided in standardized sizes. Compur shutters were marketed with smaller lenses (sizes #00 to #3), while Compound shutters continued to be provided for larger sizes (#4 and #5).[10]

Compur shutter dimensions[11]
Size
Dimension
#00 #0 #1 #2 #3
Body diameter 45.2 mm (1.78 in) 58 mm (2.3 in) 70.5 mm (2.78 in) 80.5 mm (3.17 in)
Front lens thread M22.5-0.5 M29.5-0.5 M40-0.75 M45.75-0.75 M58-0.75
Rear lens thread M36-0.75
Depth 16 mm (0.63 in) 20 mm (0.79 in) 26.5 mm (1.04 in)
Front to iris 9.3 mm (0.37 in) 10.2 mm (0.40 in) 10.75 mm (0.423 in) 14.5 mm (0.57 in) 31.5 mm (1.24 in)
Mount flange thread M25.0-0.5 M32.5-0.5 M39-0.75 M50-0.9 M62-0.75
Lens board hole diameter 26.3 mm (1.04 in) 34.6 mm (1.36 in) 41.6 mm (1.64 in) 52.5 mm (2.07 in) 65 mm (2.6 in)
Maximum iris diameter 17.4 mm (0.69 in) 24 mm (0.94 in) 30 mm (1.2 in) 35 mm (1.4 in) 45 mm (1.8 in)
 
Early Compur shutters used a dial at the 12 o'clock position to set the shutter speed; later versions used a ring coaxial with the lens.

As introduced, the Compur leaf shutter used a dial to set shutter speeds; the early dial-set versions were succeeded by the rim-set version in 1927,[1] which moved the shutter speed control to the outer rim of the shutter.[12] A self-timer mechanism was added in 1928, which was labelled Compur S.[13][14]

The Compur leaf shutter initially provided speeds of up to 1250 sec; the later models (denoted by Compur-Rapid) extended the fastest shutter speed to 1500 (#00) and 1400 (#0) in 1935.[13] AGC released the similar Prontor leaf shutter design in 1935.[1] The fastest speed should be selected prior to cocking the shutter, as a stiff secondary spring is engaged with the fastest speeds; other speeds may be selected after the shutter is cocked. In addition, the self-timer cannot be used with the fastest shutter speed.[15] Early versions use three leaf blades, while Compur-Rapid versions used five.[11] Flash synchronization was added via a coaxial PC terminal on the rim of the shutter in 1951, which bore the Synchro-Compur branding. Synchro-Compur shutters have an additional lever painted green, which allows the user to select electronic flash synchronization ("X") or flashbulb sync ("M").[15] Some Compur shutters have a trailing -P, indicating these shutters offer "press to focus" functionality. A separate button is provided that allows the photographer to open the shutter leaves to check focus on the ground glass without changing the shutter speed setting or tripping the shutter.[11]

In the early 1970s, Deckel introduced electronically controlled shutters, branded as Compur-electronic. The 4.5 V PX21 battery required to operate these shutters is now out of production.[11]

Exposure value

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F.Deckel developed the exposure value (EV) scale, also known as the Light Value Scale, which is a single number that measures scene illumination on a base-2 logarithmic scale. Each EV corresponds to several combinations of shutter speed and aperture settings that provide the proper exposure for the illumination of the scene.[16] The EV scale was first used on Synchro-Compur shutters displayed at Photokina 1954.[17]

Deckel-mount lenses

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In the late 1950s, Deckel introduced a bayonet lens mount which was used mainly with 35mm leaf-shutter cameras built in Germany, including the Kodak Retina IIIS, Kodak Retina Reflex S, Braun Paxette Reflex, and Voigtländer Bessamatic. DKL-mount lenses for the Kodak cameras were made by both Schneider-Kreuznach and Rodenstock, while Voigtländer made their own lenses for the Bessamatic line. DKL-mount lenses became less popular as focal-plane shutter cameras became more prevalent in the 1960s, and production ceased by the early 1970s.

The original bayonet was introduced in 1956 with the Voigtländer Vitessa T, followed by the Braun Colorette Super II in 1957, which shared the 44.7 mm (1.76 in) flange focal distance with the earlier Exakta system. Although the DKL-mount system is ostensibly compatible across manufacturers, camera manufacturers introduced variations in the mounting lug profiles and inclusion of an aperture control ring to physically prevent the attachment of lenses from other DKL-mount systems.[18] For instance, the Schneider-Kreuznach and Rodenstock lenses made for the Kodak Retina S-mount do not fit Voigtländer cameras directly; a small physical modification to the mounting lugs will make them compatible. This was intended to prevent Voigtländer photographers from using less expensive Retina lenses.[19]

DKL lens mount cameras include seven distinct variants (the earliest models released, Voigtländer Vitessa T and Braun Colorette Super II, share the same physical mount):

DKL-mount variants[18]
Lens
Camera
ENNA Rodenstock Schneider Kreuznach Staeble [de] Steinheil [de] Voigtländer
Balda Baldamatic III   No   No   Yes: Curtagon 2.8/35, Xenon 1.9/50, Xenar 2.8/50, Tele-Xenar 4/135   No   No   No
Braun Colorette Super II[a]   No   Yes: Eurygon 4/35, Ysarex 2.8/50, Rotelar 4/85 & 4/135   Yes Radiogon 4/35, Xenar 2.8/50, Tele-Arton 4/85   No   Yes: Culmigon 4.5/35, Culminar 2.8/50   No
Paxette Reflex   Yes: Lithagon 3.5/35   Yes: Rotelar 4/135   Yes: Xenar 2.8/50   Yes: Ultralit 2.8/50   Yes: Culmigon 4.5/35, Quinon 1.9/50   No
Iloca Electric   No   Yes: Eurygon 4/35, Heligon 1.9/50, Ysarex 2.8/50, Rotelar 4/135   No   No   Yes: Culmigon 4.5/35, Quinon 1.9/50, Culminar 2.8/50   No
Kodak Retina IIIS, Retina Reflex S / III / IV, Instamatic Reflex   No   Yes: Eurygon 2.8/30, Eurygon 4/35, Heligon 1.9/50, Ysarex 2.8/50, Rotelar 4/85 & 4/135   Yes: Curtagon 4/28 & 2.8/35, Xenon 1.9/50, Xenar 2.8/45 & 2.8/50, Tele-Arton 4/85, Tele-Xenar 4/135 & 4.8/200   No   Yes: Culminar 2.8/50   No
Voigtländer Bessamatic, Ultramatic   No   No   No   No   No   Yes: Skoparex 3.4/35, Skopagon 2/40, Color-Skopar X 2.8/50, Color-Lanthar 2.8/50, Septon 2/50, Dynarex 3.4/90 & 4.8/100, Super-Dynarex 4/135, 4/200, & 5.6/350, Zoomar 2.8/36~82
Vitessa T[b]   No   No   No   No   No   Yes: Skoparet 3.4/35, Color-Skopar 2.8/50, Dynaret 4.8/100, Super-Dynaret 4/135
Wirgin Edixa electronica   No   No   Yes: Curtagon 4/28 & 2.8/35, Xenon 1.9/50, Xenar 2.8/50, Tele-Xenar 4/135   No   Yes: Culminar 2.8/50, Quinon 1.9/50   No
DKL-mount lenses
Focal length Aperture Manufacturer Name Construction Min. Focus Accessory size Notes / Refs.
Wide-angle lenses
28 mm f/4 Schneider-Kreuznach Retina Curtagon 7e/6g 3.0 ft (0.91 m) 60 mm [20][21][22]: 29 [19]
30 mm f/2.8 Rodenstock Retina Eurygon 7e/6g ? 60 mm [20][19][23]: Fig.19 
35 mm f/2.8 Schneider-Kreuznach Retina Curtagon 6e/6g[c] 3.0 ft (0.91 m) 32 mm [20][21][22]: 29 [19]
35 mm f/3.4 Voigtländer Skoparex 6e/5g 3.3 / 1.3 ft (1.0 / 0.4 m)[d] 40.5 mm [24][25]
35 mm f/4 Rodenstock Retina Eurygon 5e/5g ? [20][26][23]: Fig.19 
35 mm f/4 Schneider-Kreuznach Radiogon 5e/4g ? ? [27]: 108 
40 mm f/2.0 Voigtländer Skopagon 9e/6g 3.0 / 1.6 ft (0.9 / 0.5 m)[d] 54 mm [24][25]
Standard / Normal lenses
Focal length Aperture Manufacturer Name Construction Min. Focus Accessory size Notes
45 mm f/2.8 Schneider-Kreuznach Xenar 4e/3g
(Tessar)
3.3 ft (1.0 m) [21]
50 mm f/1.9 Rodenstock Retina Heligon ? ? 60 mm [20][22]: 29 
50 mm f/1.9 Schneider-Kreuznach Xenon 6e/4g
(Double-Gauss)
2.0 ft (0.61 m) 60 mm [20][21][22]: 29 [27]: 112 
50 mm f/1.9 Steinheil [de] Quinon 6e/4g
(Double-Gauss)
? ? [27]: 108 
50 mm f/2.0 Voigtländer Septon 7e/5g 3.0 / 2.0 ft (0.9 / 0.6 m)[d] 54 mm [24][28]
50 mm f/2.8 Rodenstock Retina Ysarex 4e/3g
(Tessar)
? 32 mm [20][26][22]: 29 [23]: Fig.19 
50 mm f/2.8 Schneider-Kreuznach Retina Xenar 4e/3g
(Tessar)
? 32 mm [20][26][22]: 29 
50 mm f/2.8 Steinheil [de] Culminar 4e/3g
(Tessar)
? ? [27]: 103 
50 mm f/2.8 Voigtländer Color-Lanthar 3e/3g 3.3 ft (1.0 m) 40.5 mm [24][28]
50 mm f/2.8 Voigtländer Color-Skopar X 4e/3g
(Tessar)
3.3 / 2.0 ft (1.0 / 0.6 m)[d] 40.5 mm [24][28]
Telephoto lenses
Focal length Aperture Manufacturer Name Construction Min. Focus Accessory size Notes
85 mm f/4 Schneider-Kreuznach Retina Tele-Arton 5e/4g 6.0 ft (1.8 m) 32 mm [20][21][22]: 29 [27]: 110 
85 mm f/4 Rodenstock Retina Rotelar 5e/4g ? 32 mm [20][26][22]: 29 [23]: Fig.19 
90 mm f/3.4 Voigtländer Dynarex 5e/4g 6.6 ft (2.0 m) 40.5 mm [24][29]
100 mm f/4.8 Voigtländer Dynarex 6e/4g 3.3 ft (01.0 m) 54 mm [24][29]
135 mm f/4 Schneider-Kreuznach Retina Tele-Xenar 5e 14 ft (4.3 m) 60 mm [20][21][e]
135 mm f/4 Rodenstock Retina Rotelar 5e/4g ? 60 mm [20][26][23]: Fig.19 [e]
135 mm f/4.0 Voigtländer Super-Dynarex 4e/3g 13.1 ft (4.0 m) 40.5 mm [24][30]
200 mm f/4.0 Voigtländer Super-Dynarex 5e/4g 27.9 ft (8.5 m) 77 mm [24][30]
200 mm f/4.8 Schneider-Kreuznach Retina Tele-Xenar 7e 28 ft (8.5 m) [21]
350 mm f/5.6 Voigtländer Super-Dynarex 7e/6g 91.9 ft (28.0 m) 95 mm [24][30]
Zoom lenses
Focal length Aperture Manufacturer Name Construction Min. Focus Accessory size Notes
36–82 mm f/2.8 Voigtländer Zoomar 14e/11g 4.3 ft (1.3 m) 77 mm [24][31][32]
Notes
  1. ^ Lenses are compatible with the Voigtländer Vitessa T
  2. ^ Lenses are compatible with the Braun Colorette
  3. ^ Kodak literature states 5e.[21]
  4. ^ a b c d Original (Series 1) lenses had longer minimum focus distance, which was improved in later versions.
  5. ^ a b Accepts "T I/60" close-up lens to shorten minimum focusing distance.[26]

References

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  1. ^ a b c d e f g h i j k Riess, Klaus-Eckard. "Up and Down with Compur: The development and photo-historical meaning of leaf shutters". Translated by Stoddard, Robert. Archived from the original on 26 September 2013.
  2. ^ "Deckel FP1 Universal Precision Milling Machine". Lathes UK. Retrieved 18 August 2023.
  3. ^ "Deckel FP1 Universal Precision Milling Machine". Lathes UK. Retrieved 18 August 2023.
  4. ^ "Deckel FP1 Universal Precision Milling Machine". Lathes UK. Retrieved 14 March 2023.
  5. ^ "We wrote history – not only in gas detection". Compur Monitors. Retrieved 13 March 2023.
  6. ^ "Deckel FP1 Universal Precision Milling Machine". Lathes UK. Retrieved 18 August 2023.
  7. ^ "ISOG Technology - Innovative Solutions to Optimize Grinding". ISOG Technology. Retrieved 18 August 2023.
  8. ^ "Precision Surfacing Solutions". Precision Surfacing Solutions. Retrieved 18 August 2023.
  9. ^ US grant 1053152A, Christian Bruns & Heinrich Bruns, "Objective-shutter", issued February 18, 1913 
  10. ^ Purdum, Ernest (2006). "Shutters - History and Use". largeformatphotography.info. Retrieved 13 March 2023.
  11. ^ a b c d "Compur Shutters". S.K. Grimes. Retrieved 13 March 2023.
  12. ^ "Leica B (Compur)". Pacific Rim Camera. Retrieved 13 March 2023.
  13. ^ a b Barnes, Darron (31 July 2012). "100 Years since first Compur Shutter was Introduced". Milly's Cameras. Retrieved 13 March 2023.
  14. ^ Holden, T. T. (February 1938). "How Camera Shutters Work". Modern Mechanix. Vol. XIX, no. 4. Fawcett Publications, Inc. pp. 112–113, 132. Retrieved 13 March 2023.
  15. ^ a b "How to use a Compur Shutter". Classic Petrakla Cameras. Retrieved 13 March 2023.
  16. ^ Wolbarst, John (July 1957). "LVS: What It Is, How to Use It". Modern Photography. pp. 58–61, 110.
  17. ^ "Keppler's Value 25: Light Value Scale". Mike Eckman dot com. 7 December 2018. Retrieved 14 March 2023.
  18. ^ a b Neuhaus, Horst (12 January 2017). "Bajonett-compur / DKL oder das 'Deutsche Einheitsbajonett'" [The Compur DKL Lens Bayonet or the 'Standard German Bayonet']. Photo but More (in German). Retrieved 13 March 2023.
  19. ^ a b c d "Bessamatic / Objektive (Fremdobjektive)". Der Klinterklater (in German). Retrieved 10 March 2023.
  20. ^ a b c d e f g h i j k l "Kodak Retina Reflex III" (PDF) (in German). Kodak AG. January 1961. Retrieved 10 March 2023.
  21. ^ a b c d e f g h "Kodak Instamatic Reflex Camera ... does simply everything, and everything simply" (PDF). Eastman Kodak. January 1969. Retrieved 10 March 2023.
  22. ^ a b c d e f g h "Kodak Retina IIIS Camera" (PDF). Kodak. April 1960. Retrieved 10 March 2023.
  23. ^ a b c d e Naumann, Helmut (1–5 November 1965). Photographic Optics: A Status Report. 98th Technical Conference. Society of Motion Picture & Television Engineers Inc.
  24. ^ a b c d e f g h i j k "Bessamatic / Objektive" [Bessamatic / Lenses]. Der Klinterklater (in German). Retrieved 10 March 2023.
  25. ^ a b "Bessamatic / Objektive (Skoparex / Skopagon)". Der Klinterklater (in German). Retrieved 10 March 2023.
  26. ^ a b c d e f "Kodak Retina IIIS mit Belichtungsautomatik" [Kodak Retina IIIS with automatic exposure] (PDF) (in German). Kodak AG. September 1958. Retrieved 10 March 2023.
  27. ^ a b c d e Neblette, C. B. (1959). Photographic Lens Manual And Directory. New York, New York: Morgan & Morgan, Inc. LCCN 59-11726.
  28. ^ a b c "Bessamatic / Objektive (Lanthar / Skopar / Septon)". Der Klinterklater (in German). Retrieved 10 March 2023.
  29. ^ a b "Bessamatic / Objektive (Dynarex)". Der Klinterklater (in German). Retrieved 10 March 2023.
  30. ^ a b c "Bessamatic / Objektive (Super-Dynarex)". Der Klinterklater (in German). Retrieved 10 March 2023.
  31. ^ "Bessamatic / Objektive (Zoomar)". Der Klinterklater (in German). Retrieved 10 March 2023.
  32. ^ "Zoom Lens for 35-mm. Camera Shoots Still Photos". Popular Science. Vol. 174, no. 5. Popular Science Publishing Co., Inc. May 1959. p. 187. Retrieved 13 March 2023.
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