other Mamiya cameras in my collection
Mamiya/Sekor DTL 500 [1968 - 74*]
The Mamiya DTL 500 and 1000 models were introduced in January 1968. The 500 has a top shutter speed of 1/500th sec., while the 1000 has a speed of 1/1000th sec. The 1000 has a self timer, which the 500 lacks. The 500 was sold with an f/2.8 or f/2 Auto Mamiya/Sekor lens, while the 1000 was offered with an f/1.8 or f/1.4. Otherwise, the two cameras are identical. In 1969, Mamiya launched a DTL 2000 (the specification of which is self explanatory).
Dual Through the Lens light metering. A switch to the user's left side of the lens mount allows the selection of an averaging pattern, or spot metering. There are two CdS cells for average brightness metering and a third for spot metering. The spot metering area is marked by a square outlined at the bottom of the viewfinder. In both options, correct exposure is set via a viewfinder centre-the-needle system. The DTL models were the first SLRs to offer this dual metering facility.
The DTLs have no linkage between the light meter circuit and the selected f-stop, and therefore the lens needs to be stopped down to take an accurate exposure reading, however, DTL compatible lenses were equipped with a fully automatic diaphragm. Once a light reading has been taken and the exposure parameters set, a scene can be viewed through a wide open lens and, when the shutter is tripped, the lens automatically stops down again to the set aperture for the moment of exposure ... and then re-opens.
The film wind lever incorporates a meter activation/aperture stop-down switch. The lever is first pulled away from the camera body until it clicks into an offset position, and a
meter OFF locking button pops-up (the cap on top of the wind lever's central axis). The wind lever is then pressed inwards against spring pressure, which stops down the lens and activates the meter circuit. The switching mechanism constricts a loose-fit metal band around the battery when the wind lever is pushed inwards, allowing the metering circuit to draw a current. Releasing the pressure on the film advance lever causes the lens diaphragm to open up to its widest aperture. To switch off the meter, the cap on top of the wind lever's central axis must be pressed. Then the wind lever can be returned to its rest position - flush with the camera body.
Like many other models of the time, not all possible aperture and shutter speed combinations are within the range of the meter with the fastest and slowest films loaded. In these circumstances the metering system is automatically disengaged, and the viewfinder needle pointer moves upward above the viewfinder plus (+) symbol. This is a positive indicator, since the rest/off position is below the minus (-) symbol. Mamiya did not publish details of meter cut-off points in the camera's instruction manual. The metering circuitry is unusual for the time because it requires a 1.5v silver-oxide battery, rather than a mercury cell.
The lens fitting is a Praktica M42 thread, but
Auto lenses are required for the auto-diaphragm mechanism to work. The user manual warns that, when changing lenses, always LOCK the meter in the OFF position by depressing the button on top of the film advance lever: if the meter is ON during the changing of an automatic lens, serious damage may result!
* I can't establish when DTL production ceased, but the camera was still on sale in 1972. According to a 1971/2 photographic equipment catalogue published by Hastings based retailers Gifford Boyd, the DTL 500 with an f/2 Sekor lens cost £118.99. In 1971, the average UK salary as £166.99 per month. The replacement models were the 1974 DSXs, so I guess the DTLs were sold up to that time?
Lens mount: Praktica-Mamiya/Sekor, M42 mount variant.
Focus: Fresnel lens with micro dia-prism centre spot. Bracket markings indicate location of spot meter reading area (6% of field).
Shutter: Cloth Focal plane with speeds from 1 sec., to 1/500th sec., plus B.
Meter: Stop-down TTL, with two separate metering systems with one CdS meter cell positioned on the back of the reflex mirror (spot system), plus cells on each side of the viewfinder eyepiece (averaging system). Viewfinder "S" and "A" symbols indicate the metering system being used. Film advance lever switches metering system on and actuates diaphragm of automatic lenses.
Exposure: Viewfinder centre-the-needle system.
Film Speed: 25 to 3200 ASA (15 to 36 DIN).
Flash: FP and X contact ports. X-sync speed of 1/60th. Removable accessory shoe.
Film Advance: 160° ratchet type lever. Approx 30° meter ON stand-off.
Frame Counter: Automatic count-up and reset.
Rewind: Via crank and bottom release button.
Size: 148 x 95 x 51mm (W x H x D).
Weight: 725g (body only).
Battery: 1.5v SR44 type.
I purchased this camera in August 2018 - in fact I got a pair for £14.00. Both were described as being in FWO, with working meters: this seems to be a weak point with DTLs. To my amazement, both cameras are in FWO, clean, and cosmetically good, although one has a few tiny dings. The light seals are perished, but they always are.
The DTL 1000 was given a favourable review by Ron Spellman in the November 1968 edition of
Photography, and in US Camera magazine. On paper, the DTL appears to be a good camera: it comes from a respected stable; it has some advanced features for the time (despite being slightly behind the market leaders with its stop-down metering); it has quirkiness; it uses a common and modern battery.
In the hand, my expectation was the DTL would be big, boxy and ... well ugly. It's just a personal view (and somewhat tongue-in-cheek), but Mamiya were good at making big cameras, and did not seem to know how to make them small. I have been pleasantly surprised to discover that the camera is very nice. Yes it is biggish, and it is boxy, but it's also well made, solid, and rather likeable. Regardless of personal opinions, a DTL belongs in any camera collection due to its unique metering switch, and for being the first 35mm SLR to offer dual metering patterns.
A small number of Internet commentators report that there is a compatibility issue with SMC Takumar lenses due to a lug on the rear of the lens, which (on a Pentax body) moves with the aperture dial and enables the use of open-aperture metering. This prevents the lens being screwed fully home on a DTL. So what? - I don't believe the lack of compatibility with a lens made some years later is much of an issue. Whatever - I hope I can now find an Auto Mamiya/Sekor lens for my DTL: it's just always nice to have the correct original lens.