RARE TRAVEMAT TTL Meter Prism EXAKTA A SCHACHT ULM Germany
Item History & Price
| Reference Number: Avaluer:20040518 | Model: travemat ver.2 |
| Brand: A. Schacht Ulm Exakta | Country/Region of Manufacture: Germany |
| UPC: Does not apply |
The Travemat finder ver 2- Meter needle not moving!
In the late Sixties, TTL metering was quickly becoming a standard in better SLR cameras. Most Japanese models had it already, and even some East-German ones (like the popular Practica LLC) did. But not Exakta (although Ihagee had a prism with a non-TTL, uncoupled selenium meter largely ignored by the market, because of lack of advertising).
The gap was filled by two companies.
In 1966 A Schacht from Ulm, West Germany, introdu...ced a TTL metering prism named Travemat, which stayed in production at least until 1970 in three slightly different versions.In 1968 Harwix of West Berlin started making a similar device under the name of Examat. (According to Hummel, the design was by Ihagee.)Because of the hard-currency origin of the Travemat and Examat prisms, they were never available in Communist-dominated countries; a common policy was to pay the "real money" for parts or components only if the final product was later sold for hard currency.
Those found of eBay are usually non-functional or always broken!
Both prisms used a CDS (cadmium sulfide) photo-resistor overlooking the finder ground-glass. By measuring the current caused by a constant battery voltage, they were effectively metering the light reaching the image plane (the ground-glass is the image plane); the most reliable and accurate way of doing it.
As the Exakta lens mount was missing any aperture coupling to the camera body, the metering was done by stepping the aperture down until the meter needle matched the mark in the finder. Full-aperture metering was also possible, but it required a manual transfer of the metered value to the aperture ring. As inconvenient as the process may seem today, its introduction was, indeed, a major step ahead.
The Travemat, in spite of its 1966 vintage, would work with any Exakta bodies starting from the VX of the 1950; the TL marking on the camera body was just marketing.
This is the A&R v2, with full-aperture metering option. In the first picture you can (barely) see the battery compartment cover on the left side. The knurled, metal lever on the top is the on/off switch.
The Travemat is powered with a single PX-13 (PX625) mercury cell, with a 1.35V of voltage; it should last for at least a year under normal usage. Mercury batteries are no longer made or sold (at least in the States) because of environmental concerns, but Weincell is making a zinc-oxide MRB-625, supposed to be an exact functional equivalent.
Interestingly, the Travemat prism, in a departure from Exakta principles, did not accept interchangeable viewing screens. Instead, it has a fixed Fresnel screen with a matte ring and a microprism circle in the center. This was due to the fact that various screens may have various light reflection which would bias the meter indications. (And indeed, the Examat finder, which allowed interchangeable screens, required meter adjustment after every screen change.)
A quick comparison also shows that as a general-purpose viewing system, the Travemat prism does not quite match standard Exakta prism. The viewed frame is significantly smaller and less bright than when viewed with a standard Exakta screen (for example, the P.4 prism I'm using with my other VX 1000).
Aguila and Rouah (2003) list three versions of the Travemat prism:
Version 1 does not allow for full-aperture metering (and is missing the inner aperture disk on the prism top; accepted film speeds range from ASA 6 to 400;Versions 2 and 3 allow for full-aperture metering (with manual transfer, as mentioned above), and the ASA range is from 6 to 1600. The differences between v2 and v3 are only in the cosmetics of the aperture disk.A&R specify the film speed range for Versions 2 and 3 as ASA 6 to 800, but the top value was really ASA 1600.
While this value is not marked on the ASA ring for lack of space, you could use the DIN scale to set 33 DIN, which is ASA 1600.
In the late Sixties, TTL metering was quickly becoming a standard in better SLR cameras. Most Japanese models had it already, and even some East-German ones (like the popular Practica LLC) did. But not Exakta (although Ihagee had a prism with a non-TTL, uncoupled selenium meter largely ignored by the market, because of lack of advertising).
The gap was filled by two companies.
In 1966 A Schacht from Ulm, West Germany, introdu...ced a TTL metering prism named Travemat, which stayed in production at least until 1970 in three slightly different versions.In 1968 Harwix of West Berlin started making a similar device under the name of Examat. (According to Hummel, the design was by Ihagee.)Because of the hard-currency origin of the Travemat and Examat prisms, they were never available in Communist-dominated countries; a common policy was to pay the "real money" for parts or components only if the final product was later sold for hard currency.
Those found of eBay are usually non-functional or always broken!
Both prisms used a CDS (cadmium sulfide) photo-resistor overlooking the finder ground-glass. By measuring the current caused by a constant battery voltage, they were effectively metering the light reaching the image plane (the ground-glass is the image plane); the most reliable and accurate way of doing it.
As the Exakta lens mount was missing any aperture coupling to the camera body, the metering was done by stepping the aperture down until the meter needle matched the mark in the finder. Full-aperture metering was also possible, but it required a manual transfer of the metered value to the aperture ring. As inconvenient as the process may seem today, its introduction was, indeed, a major step ahead.
The Travemat, in spite of its 1966 vintage, would work with any Exakta bodies starting from the VX of the 1950; the TL marking on the camera body was just marketing.
This is the A&R v2, with full-aperture metering option. In the first picture you can (barely) see the battery compartment cover on the left side. The knurled, metal lever on the top is the on/off switch.
The Travemat is powered with a single PX-13 (PX625) mercury cell, with a 1.35V of voltage; it should last for at least a year under normal usage. Mercury batteries are no longer made or sold (at least in the States) because of environmental concerns, but Weincell is making a zinc-oxide MRB-625, supposed to be an exact functional equivalent.
Interestingly, the Travemat prism, in a departure from Exakta principles, did not accept interchangeable viewing screens. Instead, it has a fixed Fresnel screen with a matte ring and a microprism circle in the center. This was due to the fact that various screens may have various light reflection which would bias the meter indications. (And indeed, the Examat finder, which allowed interchangeable screens, required meter adjustment after every screen change.)
A quick comparison also shows that as a general-purpose viewing system, the Travemat prism does not quite match standard Exakta prism. The viewed frame is significantly smaller and less bright than when viewed with a standard Exakta screen (for example, the P.4 prism I'm using with my other VX 1000).
Aguila and Rouah (2003) list three versions of the Travemat prism:
Version 1 does not allow for full-aperture metering (and is missing the inner aperture disk on the prism top; accepted film speeds range from ASA 6 to 400;Versions 2 and 3 allow for full-aperture metering (with manual transfer, as mentioned above), and the ASA range is from 6 to 1600. The differences between v2 and v3 are only in the cosmetics of the aperture disk.A&R specify the film speed range for Versions 2 and 3 as ASA 6 to 800, but the top value was really ASA 1600.
While this value is not marked on the ASA ring for lack of space, you could use the DIN scale to set 33 DIN, which is ASA 1600.
