My Mamiya: Here I Go Again...The 1000 DTL

mamiya/sekor 1000 DTL with its standard AUTO mamiya/sekor 55/1.8 lens

     Well...it's happened. A Mamiya 35mm SLR has finally found its way into my grubby little paws. Sitting forlornly in a local thrift store, encased in a period vinyl case upholstered in the finest of green corduroy, with the assorted detritus of Kodak lens tissues, a bag of eyecups (none of which fit the eyepiece, of course ;-)), and a fourth-party flash and bracket, it soon came home with my friend after a quick exchange of text messages. Three hours later, I opened the case to that particular aroma only decades of storage can provide. Not unpleasant at all; in fact, distinctively delightful to a vintage camera nerd ;-). The original (n)ever-ready mamiya/sekor case was doing the typical crack & crumble as is the wont of such; nevertheless, it had done its job of protecting the important bits inside: a 1000 DTL and its accompanying AUTO mamiya/sekor 55/1.8 lens. A quick visual perusal showed nary a ding or dent, just an accumulation of dirt and light surface wear on the prism housing. The lens looked clear...the viewfinder pretty dusty...and then came the letdown... ​

    ​ ...when I went to focus, the ring twisted far too easily...and then quickly stiffened up. Aha, probably why the camera had been consigned to its padded prison with a freshly-loaded roll of Fuji Superia 800 over twenty years ago (my best guess, anyways). OooKay. So now I had a project: an exploratory procedure for the lens; clean the focusing screen somehow; and find out if the camera itself actually works. 

    I started with the latter (no point in doing the other stuff if the camera turned out to be a brick ;-)). The 1000 DTL is fully mechanical, so the first order of business was to check the shutter. Pleasant Surprise #1: the shutter was not cocked when the camera was last put away (YAY!). Pleasant Surprise #2: the shutter speeds showed proper delineation (at least by the fuzzy eye & ear test ;-)). Alright, that was one less worry, now onto the bugaboo for many a 1960s SLR with a built-in meter - would said meter be functional? Pleasant Surprise #3: the DTLs were among the first SLRs (if not the first) to use the then-newfangled S76 (aka SR44; aka 357) silver oxide cell that is still readily available, with no need to monkey around adjusting the voltage of the metering circuit. You can also use the alkaline A76/LR44 version, if you must. Upon opening the battery compartment, a spent A76 popped out with the telltale blue crystals of corrosion from the leakage of the battery. Fortunately, the corrosion was minimal and quickly addressed with a couple Q-tips soaked in vinegar. Pleasant surprise #4: upon drying the battery chamber, insertion of a single new SR44, and opening of the film advance lever roughly 15 degrees...the meter needle sprang to life in the viewfinder. Now my enthusiasm took a jump. This was going to be worth the viewfinder cleaning and lens CLA. This was now my mamiya...how could I resist? ;-)

   The 1000 DTL - An M42 Marvel

   When it debuted in 1968, the 1000 DTL (Dual Thru-the Lens) built upon the successful 1000 TL (Thru-the Lens) Series which preceded it in 1966. The TLs had been the first production SLRs to include a TTL spot meter ("partial" would have been a more appropriate descriptor for the square 10% bottom central chunk of the viewfinder that the meter measured from). The DTLs steered even harder into the curve with a 6%-coverage Spot meter (in the same location as the TL's) AND...the addition of a full-screen Averaging pattern (thus the "Dual" part of DTL :-)). The user could simply push a switch on the left bottom side of the lensmount to select between "S" and "A"; no muss, no fuss. This made the DTLs the first SLRs ever to offer a choice of metering patterns. Metering remained the stop-down variety (fortunately for Mamiya's M42 competitors; if it had been full-aperture TTL, they would have been in a world of hurt).

    It was the DTL metering that truly delineated Mamiya from the rest of the M42 stable of manufacturers at the time...besting even the all-conquering Pentax Spotmatic in that area. As far as refinement and build quality go, however, I would place the DTLs in a solid second place to the original Spotmatic (SP) and Spotmatic II (SP II) among M42 SLRs. For instance, the shutter speed dial, while sporting very distinct detents, does not move with the same precision as the Pentaxes (there is roughly double the amount of play in the DTL's dial). The same goes for the film advance: it is smooth enough on the DTL, but the ratcheting mechanism can sometimes fail to disengage completely, requiring an extra half-stroke or so to initiate the wind-on process, while there is never a hint of a miss with the ratcheted Spotmatic advance. The Pentax SP & SP II advance is simply quieter, more buttery, and just feels more finely-tuned in its operation (the Spotmatic Fs that I have tried have all been rougher in feel than their forebears and closer to the DTL but with higher effort). Tolerances are obviously tighter on the earlier Pentaxes, giving the impression of a higher-quality instrument. The DTL still feels very good, but there is no getting around the difference in feel. That said, aside from the stop-down metering, the 1000 DTL was state-of-the-art in features and the most advanced M42 body on the market upon its introduction.

    Perhaps my favorite feature of the DTL is its depth-of-field (DOF) preview mechanism incorporated into the film-winding lever: with the lever opened to its standoff position (about 15-20 degrees of rotation; which also energizes the metering circuit) you simply push it in towards the body to stop down the aperture on the lens, allowing you to take the meter reading while confirming DOF. It is very convenient and works a treat :-). Meter shut-off is also a breeze: simply push down on the button in the center of the film advance lever and it automatically swings into the closed position, breaking contact with the battery.

    The AUTO mamiya/sekor M42 lenses are similar to Super Takumars in control layout, with the (A)UTO/(M)anual lever (which can also be used for DOF preview, but it's not as convenient as pushing in the film winding lever) and aperture rings operating identically, but with the A/M lever oriented 180 degrees from the Pentax configuration. The AUTO m/s M42 lenses also focus in the opposite direction (clockwise-to-infinity) of the Super Taks (counter-clockwise-to-infinity). Internal build quality is very close, with both using aluminum-on-brass helicoids for smooth, long-lasting focusing (I still give the edge in smoothness to the Takumars :-)). However, the shallow, finely-knurled, flat-grip focusing rings of the AUTO mamiya/sekors fail to provide the same level of grip as the scalloped, coarser-knurled rings of concurrent Super Takumars (early Super Taks also had flat grips, but still with coarser knurling than the mamiya/sekors). Similar to the shutter speed dial situation, there is more play in an AUTO mamiya/sekor aperture ring than the zero-lash of a Super Takumar, but the aperture clicks, nevertheless, remain positive and distinct. Focus throw is roughly equivalent with both 55/1.8s having about a 280-degree rotation from close focus to infinity, with the Super Takumar focusing approximately 5 cm (2") closer than the AUTO Mamiya.​

  A Tune-Up for My 1000 DTL

    Speaking of lenses: I now turned my attention to the 55/1.8 AUTO mamiya/sekor. The optics looked great, with minimal internal dust and no signs of fungus or balsam separation, the second of which does seem a bit more common with these AUTO mamiya/sekor lenses than average for the era. Unscrewing the front name ring and filter thread barrel revealed the culprits responsible for the loose focusing ring: the three screws securing the ring had backed off. Mamiya had used a black, gooey, evidently petroleum-based substance of undetermined ancestry to secure the screws instead of the red lacquer used by most other manufacturers at the time. As the helicoid grease had separated over time (also resulting in the stiff movement of the helicoids), the base oil had migrated forward and softened the black goop (sorry for the burst of technical jargon ;-)), and the screws had loosened. Further disassembly, cleaning, re-greasing of the helicoids, reassembly, and re-setting of infinity focus were typical of any period MF lens. Internal fit and finish were at near-Takumar-levels, which is to say about as good as any other 35mm lens on the market at the time. The aperture ring does feel a bit less positive than an equivalent Takumar as noted above, but that is really splitting hairs. All in all, I was impressed with the build quality of the AUTO 55/1.8. 

    Next came tackling the dusty focusing screen. The top plate has to be removed to access the prism and screen assemblies. And here is where Caution #1 is in order: to do a proper job of removing the top plate...you first need to remove the bottom plate to gain access to the film winding assembly. The temptation may be great to skip this step, but you must resist ;-). Fortunately, Ron Herron has kindly provided an illustrated article on how to do this the correct way to prevent damage to the film winding lever and, not coincidentally, make the job easier in the long run. Taking the extra ten minutes or so to follow this procedure is well worth it! Caution #2: Mamiya used many brass slot-head screws to secure components in the camera, including the two flat spring assemblies that have to be removed to access the film-winding shaft. YOU MUST USE THE PROPERLY SIZED METRIC SLOTTED SCREWDRIVERS (the thickness of the blade being the most critical dimension) to have any chance of removing these screws without stripping the heads. Slow and steady torque application with the blade centered in the slot is the way to go. If you use an undersized blade and/or just try to crank on it, you WILL strip the head :-). This is one of the reasons that people often try to bypass the bottom plate procedure.

    Having successfully removed the flat springs, I then accessed the meter shutoff shaft (it is inserted inside the hollow film winding shaft), which is partially held in place by a press-fit button on the top of the winding lever. A set of precision, thin-blade, needle-nose pliers (with each jaw on one side of the shaft) levered against the bottom flange of the meter shutoff shaft and the camera chassis (again with slow and steady downward pressure) will cause the button to pop off of the top of the shaft, revealing a set-screw that secures the chrome trim ring on the film advance lever. The shaft can then be slid back in to its proper position and the two spring plates replaced to hold it in until final reassembly of the top plate. ***NOTE*** Always take plenty of pictures to remind yourself of the configuration of components as you disassemble a camera or lens step-by-step. It can be a life- or at least a hair-saver ;-).

    With the meter shutoff button removed, the rest of the film-winding lever disassembly is much easier. You now can easily access the set-screw securing the chrome trim ring in place, without having to reef on it (not the easiest thing to do with a 3mm thick, 15mm diameter piece of chrome ;-)), and scarring up the wind lever with the set screw. Use a #0 JIS crosspoint screwdriver for the both the bottom and top plate screws, if your DTL is new enough (somewhere between Serial #s 241xxx and 254xxx the change was made); otherwise, they will be slotted. There is another slotted screw under the shutter speed dial that holds down the top plate. You can also pick up a few pointers (although the bottom plate procedure is not followed, something I would STRONGLY caution against) from this video:      

    By combining the repair procedure outlined by Ron Herron with the above video, I was able to successfully clean the focusing screen and prism, with only a couple of tiny specks left and no harm done to the camera body. Removing the bottom plate did lead to an Unpleasant Surprise, though: There is a pair of brass switches (with attending red and yellow wires) consisting of thin brass plates sandwiched with a piece of black plastic. This assembly is then secured to the chassis of the camera by two non-conductive, nylon M2.5 x 4 screws (a #1 JIS or Phillips screwdriver will work). This is what allows the user to switch between Spot and Average metering and also take the stop-down reading. The trouble, after nearly 50 years, was that the black plastic piece and nylon screws both became brittle. On my Mamiya, one screw head had already broken free and was floating in the bottom of the camera. The black plastic piece had also broken in half, but was still held in place by the other intact screw and the shank of the broken screw. This had been just enough to keep the meter working, but eventual failure would have been inevitable. If I had not opened the bottom of the camera up, I would have never made this discovery, so there is an added benefit to following Mr. Herron's recommended procedure for top plate removal: you can inspect the status of the switches and screws at the same time. Fortunately, I was able to track down a multipack of M2.5 nylon screws on Amazon for under $10 USD (and, no I am not affiliated with Amazon ;-)) which included the 4mm length required. A bit of Q-Bond (check your local hardware store for the best price; Amazon is insane on that one, at least in Canada :-)) and two new screws later, the 1000 DTL was again complete and still fully functional. Replacement of the mirror bumper and light seals was the final stage in the resuscitation of the camera and lens.  

The repaired meter switch assembly with two new nylon M2.5x4 screws and a dollop of Q-Bond

  The 1000 DTL in Hand

    Make no mistake, the DTL is a full-sized handful of SLR. It is definitely of its time as far as dimensions and weight go, with only the aforementioned Pentaxes offering a noticeably smaller and lighter package than the other usual suspects (Canon FTs, Minolta SRT-101s, Nikkormat FTns, and also the other M42 models of the period). For someone with larger mitts, the Mamiya may feel a bit more comfortable than a Spotmatic, but you really need to hold each in your hands to make that call. The right-hand controls are much closer together on the Spotmatic versus the DTL and you will likely prefer one to the other, just depending on your physiology. The longer winding lever of the DTL makes for a perceptible decrease in winding effort versus the Spottie, (there again is a tradeoff: the lower-effort, but slightly less-refined feel of the DTL versus the very precise SP & SP II). It is easier for my medium-sized index finger to turn the Pentax shutter speed dial by itself, whereas the DTL takes considerably more effort to move one-fingered due to its heavier detents and springs and the longer extension required for your index finger to reach it. The DTL shutter speed dial also has hard stops at 1000 and B (unlike the Spotmatic, with its continuous travel), so do not try to force it from 1000 to B or vice-versa. ​

Note the differing densities in right-side, top-deck layout between the 1000 DTL and the Spotmatic

​    The Mamiya's viewfinder is slightly dimmer than the Spotmatic's (and therefore, most others of the era) and the central microprism focusing aid is very fine-grained (about the same as the Pentax) compared to the Canons, Minoltas, and Nikons of the same time period. For me personally, it is a bit more difficult to focus the Mamiya than any of the others, but YMMV. It certainly is not enough to put me off using the camera, but it is something to be aware of. The Spotmatics are the only other M42-mounts that I have personal experience with and it is a close contest between the two for me. I prefer the viewfinder display, metering options, shutter, battery, and the DOF preview of the 1000 DTL, while the Spotmatic/Takumar's overall level of refinement and lighter feel of the shutter release are perceptibly better. If you are interested in an M42 system, the Mamiyas are definitely worthy of consideration. ​

    ​Lens compatibility within the M42 ecosystem is one of the major drawing cards for many enthusiasts. The DTLs are an excellent match for most pre-open-aperture metering M42 lenses and quite a few, but not all, open-aperture M42 optics. In the early-to-mid-'70s, most of the M42 manufacturers, Including Mamiya, introduced updated lens lines with an additional pin or lug to facilitate open (aka full) aperture metering. Some of these lenses are not compatible with the older M42 stop-down bodies, due to the possible interference of the lens mount screw recesses with that open-aperture pin or lug. Other than the original dimensions and aperture stop-down pin of the Praktica M42 mount, there was no standardization between the various manufacturers. Issues have been reported concerning the open-aperture Pentax Super-Multi-Coated and SMC Takumars with Mamiya TL/DTL M42 bodies. I personally have tested metal grip Super-Multi-Coated and rubber grip SMC Takumar 55/1.8s on my 1000 DTL (Serial # 622xxx) with no deleterious effects (I very carefully watched the location of the open-aperture pin in relation to the screw recesses in the lens mount as I gently turned the final 360 degrees of the lens thread in. My DTL dates from circa-1973 (ascertained by the newer-style meter switch located at the base of the meter shutoff shaft), so it is very possible that older copies may have a different lens mount screw recess that I didn't encounter.

    The takeaway: if you are going to take the chance of mounting a possibly-incompatible lens on any M42 body, proceed cautiously and NEVER force anything. There are so many lenses available that it's not worth damaging a body, a lens, or both if you are unsure about a possible lens/mount conflict. Another area to watch is for the mirror to rear element clearance of certain non-Mamiya M42 lenses focused to infinity (particularly older German and Soviet lenses, but also some Japanese optics); Mamiya was an earlier adopter of an oversized mirror to mitigate image cutoff with longer telephotos than some of their competitors, so manufacturers that used a smaller mirror in their M42 bodies would sometimes have a deeper rear-element protrusion on their lenses than Mamiya and using such lenses can interfere with the mirror flip of Mamiya bodies. ALWAYS carefully and gently thread in a new-to-you M42 lens and stop if any resistance is encountered before the lens is completely seated. If the lens threads in normally, then check if the mirror hits the back of the lens when focused at infinity (that is the furthest back the rear element will extend on the lens). If the mirror does contact the lens, simply focus the lens closer to allow the mirror to complete its swing and the shutter to fire. Then remove the lens.

  Wrap-Up

    There is a lot to like about the 1000 DTL. Operation is straightforward, especially if you read the 30-page (including covers) Owner's Manual first :-). The controls are legible and positive in operation. Overall construction is solid, with only the possible deterioration of the plastic meter switch piece and nylon screws in the bottom of the camera that stands out as something to watch for. If they look good and the meter works, just leave them be. Having the meter powered by a single S76/SR44/357 battery is a bonus. The aesthetics of the camera are clean, with the subtle splashes of real chrome on the top deck controls and the prism housing setting off the simple lines of the camera very nicely to my eye. 

    I have no qualms in recommending the 1000 DTL if one pops up in front of you, like mine did. Do be watchful for possible balsam separation with the AUTO mamiya/sekor lenses that may be included with the body. ***NOTE*** For those who are hesitant about radioactive lenses, the 55/1.4 & 55/1.8 AUTO mamiya/sekors both used thorium-impregnated elements and are "middle-of-the-road" as far as emissions in comparison to other thoriated lenses of the era, with the average 55/1.4 sitting at roughly half the level of the 7-element SMC Takumar, and the average 55/1.8 at about half the level of the average 55/1.4 (I say "average" because certain copies of both lenses have been found to have different numbers and locations of thoriated elements). We will take a closer look at the subject of radioactive lenses in a future post.

   If you are searching for the ultimate Mamiya M42 SLR, however, I would recommend the DSX 1000 (released in late-1974) over the DTL. You get an identical (or nearly identical) body internally with the addition of:  

• Open-aperture metering with mamiya/sekor SX lenses, and backwards-compatible stop-down metering with standard M42 lenses that is identical in operation to the DTL
• A small rubber handgrip, plastic-tipped film advance lever, and shutter release lock
• A hot-shoe
• Lens-mount lock with SX lenses
• Pentax Super-Multi-Coated and SMC Takumars are compatible

​    The DSX 1000s are rarer than the 1000 DTL, but if spot metering is not your bag, the Sears 1000 MX & 1000 MXB (Black) are virtually identical, except for a single, centerweighted meter pattern. They are not exactly common either, but can be had for a deal sometimes due to the lack of cachet for "Sears"-branded cameras.

    There are plenty of options for M42 SLRs out there: from Asahis to Yashicas, and nearly everywhere in between. The Mamiyas were among the most advanced when it came to metering (along with the Fujica ST-701 & -801) and were very solid cameras. If you are looking at getting into the M42 mount, you could do a lot worse than a 1000 DTL, if one finds you. And that could happen at any time. Mamma mia, indeed ;-).

  References:

    Mamiya/Sekor TL/DTL series @ http://camera-wiki.org
    Mamiya TL and DTL 35mm Cameras @ http://herron.50megs.com/DTL.htm
    Mamiya TL and DTL Top Plate Removal @ http://herron.50megs.com/topPlate.htm
    Mamiya MSX and DSX 35mm Cameras @ http://herron.50megs.com/sx.htm
    M42 Cameras @ http://mamiya-nc-m42.mflenses.com/m42_cameras.htm
    M42 Lenses @ http://mamiya-nc-m42.mflenses.com/m42_lenses.htm
    Sears 1977-78 Camera and Photographic Supplies Catalog
    mamiya/sekor 1000 DTL User Manual @ https://www.butkus.org/chinon
    mamiya/sekor DSX 1000/DSX 500 User Manual @ https://www.butkus.org/chinon