Mamiya/Sekor TL/DTL series
|Mamiya-Sekor 1000 DTL
image by Voxphoto (Image rights)
In the latter half of the 1960's, Mamiya sold a series of SLR cameras using the popular 42mm threaded lens mount, built around a spot-metering capability (not center-weighted averaging). While in most ways similar to a vast number of contemporaries from the major manufacturers of the time, this spot-metering system made them fondly remembered by many who used them, and they were sometimes claimed (by Mamiya press materials) to be one of the most advanced cameras in the world. This is undeniably an exaggeration, but the top-of-the-line DTL models were excellent performers for the time.
Indeed, the DTL 1000 was innovative and technically impressive in offering two metering modes. It also offers all the features associated with a high-end consumer or semi-professional camera--save that some but not all cameras of this time also offered open-aperture metering, a feature that Mamiya would add in their later SX models. Being based on the basic m42 mount originated by Contax and used most prominently by Pentax, the DTL lacks an interlock between the aperture ring and the meter, and could only meter with the aperture stopped down.
The models are:
- Mamiya/Sekor 500 TL
- Mamiya/Sekor 1000 TL
- Mamiya/Sekor 500 DTL
- Mamiya/Sekor 1000 DTL
- Mamiya/Sekor 2000 DTL
The TL models were introduced in 1966, the 500 and 1000 DTL in January 1968, and the 2000 DTL was introduced at Photokina 1968.
These models may be grouped together, as they all share the same basic body; their differences are clearly reflected in their model designations. The numeral represents the highest shutter speed (1/500, 1/1000 or 1/2000 of a second); the letters TL or DTL signified Through the Lens or Dual Through the Lens light metering. The "500" models typically lack a self-timer, and the TL models lack average metering.
The later DTL dual-metering models introduced a switch beside the lens mount which allowed the photographer to select between the averaging meter pattern (the entire frame, roughly unweighted) and the "spot" meter (actually a square area) with a viewfinder indication of the mode selected. At the right hand of the viewfinder is a fairly diminutive needle with indicators etched into the focusing screen: a plus, a backwards C shape that surrounds the needle when the exposure is correct, and a minus.
The spot meter is actually a square zone at the bottom center of the viewfinder, marked by brackets and noticeably darker than the rest of the frame. This is because the CDS cell is inside the mirror behind a semi-silvered patch. The brackets indicate the approximate extent of this area more clearly. Inside this area is an "S" for spot metering, and just outside it on the right is an "A" for averaging. A small triangular flag points to the selected mode so that the photographer does not even have to touch the switch to know what mode is selected.
The concept of having spot metering in an SLR was a unique feature for its day, and was protected by U.S. Patent No. 3,612,703, filed February 29, 1968. Interestingly, the single metering mode offered by the TL models was the "spot" mode, not the averaging mode one might expect. Thus it was the Mamiya TL and not Pentax who implemented the original concept of Pentax's Spotmatic prototype.
The spot is fairly well-defined and gives a reading that doesn't have much bleed-over from outside the indicated zone, though its spot is fairly large and with a 50mm lens it has a viewing angle somewhat larger than the 1 degree of most handheld spot meters such as those made popular by Pentax, Minolta et al. and used often with large format cameras. It remains however one of the earliest and cheapest cameras that a competent photographer can execute zone-system photography on with some degree of accuracy, though there are limitations inherent in roll film as compared to sheet film that limit the flexibility of the zone system. Ansel Adams' trilogy of textbooks on the subject of photography elaborate further on zone system photography on small and medium format. At any rate spot metering in an SLR is associated with high-end German cameras and its presence on the TL and DTL series and the followup SX series is rather exceptional, even if its execution is less precise than on some cameras.
As mentioned above, the meter operates only when the lens is stopped down to shooting aperture. But it may be less than obvious at first glance how one is intended to stop down the lens and activate the meter on a TL/DTL body. Mamiya made an interesting choice to have the film-wind lever also double as the stop-down lever and meter switch. The user pulls the lever away from the body until it clicks; after which, pressing the lever inwards against spring pressure stops down the lens and activates the meter circuit. To put the camera away without risking accidentally draining the single 1.5v silver-oxide meter battery, one stows the wind lever in its "off" position by clicking the round cap atop its axis. The switching mechanism is also unusual: instead of a fixed contact, the metal band around the battery is a loose fit until the wind lever is pushed inwards and the band is pressed in tight against the battery to complete the circuit.
The Mamiya/Sekor lenses are somewhat sought after today as having a fairly good reputation and being compatible with most m42 cameras. The camera itself uses the standard automatic-aperture variation of the m42 thread mount similar to that used on most Pentax Spotmatics and many other cameras. An enormous variety of lenses fit this camera, though some do not and some can even become stuck.
The Pentax Takumar Super-Multi-Coated lenses introduced with the Spotmatic F are not recommended for the TL and DTL. At best some of them will not screw down completely, as the small pin on the outside rear face of the lens will catch on the trailing edge of one of the boltholes on the front of the camera, preventing it from being tightened further (though not preventing it from being unscrewed). Forcing it will damage the lens. At worst the pin can become trapped in the bolthole and trap the lens in an incompletely mounted position, rendering the camera useless and requiring extensive disassembly of lens and/or camera to remove it. While far from the only camera to have this problem the TL/DTL seems to be one whose construction makes bypassing this problem impossible, unlike on say, the Zenit E.
There are other lenses which will not mount or which will damage the camera. A particularly nasty case is non-retrofocal wide-angles that are designed to be used with an SLR with the mirror locked up. These can make contact with and ruin the mirror.
Even by the SLR standards of their day, the TL and DTL models were at the large and heavy end of the spectrum. A 1000 DTL with its original 50mm f/1.4 lens weighs 1,077g (2 lb. 6 oz.) and measures 150 x 94 x 100 mm (W x H x D).
The self timer is wound by the customary lever on the front of the camera, but the lever swings clockwise, the opposite direction to the vast majority of SLR self timers, so the photographer can comfortably use it as a grip without accidentally charging the timer.
The cocking lever, in addition to the complicated mechanism for activating the meter, stopping down the lens and that for locking the lever in the "off" position, also features single-or-multi-stroke operation, so the photographer may, at his or her convenience, cock it in one (rather short) stroke or in any number of shorter strokes.
image by Levi Zinser (Image rights)
image by s58y (Image rights)
|500 DTL w/self timer
image by Sevesteen (Image rights)
- Type: 35mm SLR
- Format: 36x24mm on 135 film
- Viewfinder: fixed pentaprism with microprism spot and meter needle (meter selection indicator on DTL models.)
- Shutter: focal-plane shutter, rubberized-cloth, horizontal-travel type.
- Shutter speed:
- 500 models: 1s-1/500s and B
- 1000 models: 1s-1/1000s and B
- 2000 DTL: 1s-1/2000s and B
- Flash Sync: X and FP, PC socket, X-speed 1/60th
- TL models: square spot metering area, CdS, stop-down type.
- DTL models: square spot metering area and whole-field averaging, three CdS cells, stop-down type.
- Film transport: lever wind, single or multi-stroke
- Self-timer: mechanical, lever-operated
- Lens mount: m42 with automatic diaphragm
- Battery: 1x1.5 volt cell battery
- Mamiya TL Manual in HTML at Michael Butkus' Orphan Cameras
- Mamiya 1000 DTL manual at OrphanCameras.com
- 1000 TL launch advertising in the July, 1966, Popular Photography (Vol. 59, No.1; pages 16-17)
- The Mamiya TL Family at Joerg Krueger's Mamiya 35mm SLRs Homepage (archived)
- Documents (PDF) uploaded at the Apple Mac forum Mac GUI by user Dog Cow:
- Mamiya Sekor 1000 DTL Series Owner's Operating Manual
- Test Report Mamiya Sekor 1000 DTL - Photography, November 1968
- Tests Mamiya Sekor 1000 TL - Photography, May 1967
- The Big Show Ron Spillman reports on Photokina 1968 Mamiya Sekor 2000 DTL - Photography, December 1968
- The Century's Greatest Developments in SLR Cameras! Mamiya Camera Co - Camera, October 1968
- Refurbishing the Mamiya/Sekor 1000 DTL