Reprinted From Fal/1980 Issue of MODERN PHOTOGRAPHY, Article Entitled WORLD 'S BEST . ETRS In designing the ETR, Bronlca not electronically sophisticated as this the direction of G. Ando) has pro­ only brought the medium-format ­ one. With the AE-II finder, pressure duced a remarkably small, light­ shuner SLR up to date with electron­ on the release will now illumi­ weight, medium-format SLR-the ics, It also created one of the few roll­ nate the shutter speed indicating Bronica ETA. Like the previously re­ film cameras that handles like a 35. LED's directly without having to hunt leased M645, it's a 120 roll­ for the meter prism mounted switch. film deSigned around the 4.5 Note: The new ETR S introduces Minor improvements have been made x 6 cm (1 o/s x 21f.s in .) format. instead of minor but important changes. The in the strap lugs and in the camera the more familiar 6 x 6 cm (21f.s-in . electrical contacts throughout are on l off switch concentric with the square) film frame size. However, as now gold-plated for improved per­ shutter release. All these changes, you'll see, its design concept, center­ formance, important in a camera as however, do not alter our Inside Your ing around leaf-shutter lenses and in­ Camera diagrams and their utility. terchangeable film magazines, is In keeping with the ongoing trend more akin tothe 500 C / M. toward ever more compact cameras, In designing the ETR , Bronica engi­ Bronica's engineering group (under neers clearly started with a clean slate. Bronica heretofore produced only focal-plarieShU"tter 6 x 6 cm SLRs and had virtually no experience with leaf-shutter types. Nevertheless, it determined that the shortest and fastest route to a lighter, more com­ pact camera would be to remove the focal-plane shutter's many mechani­ cal parts from the camera body. Of course there are other kinds of problems associated with leaf-shutter SLRs that Bronica had to face. First of all, the shutters, which must be placed in each lens barrel, have to be mechanically connected to the cam­ era's control mechanism so they can be cocked and released. Further­ more, both of these operations must occur in a precisely ti med mechanical sequence which includes the move­ ment of the mirror and the light baffle. Considering these difficulties (in 18. Accessory shoe addition to the variability among shut­ ters built into separate lens barrels), Bronica took quite an interesting di­ rection when developing this new camera. Perhaps more significantly, Bronica successfully eoaow.ed its small, medi um- format SLR with "35mm-style" handling, placing it in a class by itself among current cameras of this type. As usual, the following detailed de­ scriptions will concentrate on the ETR's more interesting pO ints, skip­ ping the self-explanatory areas. 1. Finder prism and prism cover: Prisms are hardly unusual on me­ dium-format cameras these days, but this one is optically different from the pentaprisms found on 35mm SLRs. Indeed, if the Bronica ETR had an or­ dinary roof prism over its finder screen, you probably wouldn't be able to see anything through the finder. Why? Because there's a bulky film magazine in between your eye and the camera body which would prevent you from bringing your eye up 1. Finder prism & prism cover

3.

4. Dark slide

2.

12. Lens-information keying contacts shutter-release button

9. Multiple-exposure lever

8. Film-crank attachi to the eyepiece. As you can see in the Now that you see how difficult it is to tem is quite different. In fact, the Ma­ main drawing, the ETR's extended design a small SLR around a medium­ miya doesn't have a true inter­ roof prism is located quite far to the sized , you can appreciate changeable film magazine. rear of the finder . The large, flat Bronica's ingenu-ity. 11. Film advance I shuHer-cocking prism in front of it actually functions 3. Film holder: In producing their leaf­ mechanism. This is also quite similar as a large mirror. This mirror prism re­ shutter single-lens reflex, Bronica fol­ to the Hasselblad's in basic concept. lays the image from the finder screen lowed basically the same path taken However, the design of the ETR 's to the roof prism which, in turn, erects by Hasselblad in 1957. If you compare mechanism is simpler and. more mod­ and laterally reverses the image, our "Inside Your Camera" drawing of ular. Since this camera uses Japa­ presenting it in the proper orientation. the Hasselblad 500 C/M (June 1976, nese Seiko leaf shutters, the shutter­ Also, you have to realize that a me­ page 100) you'll find that there are cocking mechanism must be consid­ dium-format camera has inherent many similar mechanical assemblies erably different from the Hasselblad's. weight problems to begin with . Math­ common to both cameras. The film Instead of turning a key way at the end ematically, as the film width doubles, magazine is just one such mecha­ of a small shaft to cock the shutter, a the picture space quadruples, and the nism. It's remarkably similar to the large ring placed concentrically mass and weight of the camera in­ . one found on the Hasselblad 500 around the lens mount turns to cock creases as much as eight times. This series. However, while the Hasselblad the shutter (see simplified drawing on calculation doesn't even include the magazine has a slide-in film holder, this page). Let's examine the simpli­ necessity of using larger, heavier the Bronica ETR's has a hinged back fied drawing a bit to see precisely how finder prisms. As a result, a conven­ which opens downwards. But com­ these operations take place. tional pentaprism for the ETR would pared with the Bronica's ~ounterpart, As you turn the film-advance crank, easily outweigh the camera itself. the Mamiya M645, the ETR's film sys- the wheel behind crank (8) (actually the in attached to this wheel which connects or disconnects the film­ wind crank or accessory-speed grip with the camera's wind mechanism) d turns gear train (a), which advances the film by transferring its movement to the film-holder mechanism. At the same time, a spiral cam (b) turns clockwise, pushing upwards on the pin above it and pivoting lever (f) to the left. This movement causes the light baffle and mirror to come down into viewing and focusing position. Also, this cam movement causes the righthand end of lever (c) to lift sliding bar (d). This cocks the sh utter by tu rn­ ing Shutter-cocking ring (e) clockwise via a pin . The Bronica ETR's film-advance and mirror-cocking mechanisms are quite similar to the Hasselblad 500 C / M's. But due to the difference be­ tween the Com pur and Seiko shut- ters, the shutter-cocking mechanisms are dramatically different. The Hassel- blad uses a sophisticated gear train, while the ETR uses the sliding bar and ----"1Ik--7':"P---ir------brge-rmg con , bination-we'-v' de--­ scribed. Furthermore, Bronica's engi­ neers separated the film-advance mechanism from the mirror and shut­ ter-cocking mechanism. The ETR's film-advance mechanism is built onto a plate which is subsequently affixed inside the diecast body, while the mir- ror and shutter-cocking mechanism are built directly into the camera body. The Hasselblad has separate springs for the mirror mechanism and shutter-cocking escapement, while the ETR has one powerful spring be- hind the shutter-cocking sliding bar (the top part of it is visible in the sim­ plified drawing on this page) to ac­ complish both these functions. 6. Auxiliary wind lever: This is truly a revolutionary idea because it brings medium-format camera handling up Bronica ETR: Film-wind and mirror-cocking mechanisms (above), shutter­ to the level of 35mm SLRs. The ETR's cocking and electronic-information-transfer systems (below). See text. basic identity can be described as a modified Hasselblad-type, medium­ the down position. shutter speeds can still be controlled format camera, but when the acces­ This protects you against acciden­ electronically, with virtually no timing sory grip is attached, it is transformed tally removing the lens at the wrong errors. Since they had devised this into a different camera entirely. The time. The righthand end of lever (k) brilliant scheme for getting flexible grip is surmounted by a double-action serves this purpose. Only if the shut­ electronic circuitry into the ETR's wind lever. Wind the lever two short ter is cocked and not fired will lever (k) lens barrels, Bronica's engineers de­ strokes and the film is advanced and (which is located right behind the lens cided not to waste their ingenuity by the shutter's cocked. Here's how it lock/ release button (13) move left­ having it perform a single function. works. Below the lever, in the grip's ward permitting you to push in on the Why not have the lens supply expo­ midsection, is a set of bevel gears lens lock/ release button. When you sure-determining information to the which transfer the wind lever's motion release the shutter, lever (k) moves to body? In fact, this is precisely what 90° to a wheel on the side of the grip the right, and pushes against the lens happens-the camera electronically facing the camera. This wheel termi­ lock/release button preventing it communicates shutter-timing infor­ nates in a pincer-like channel, or slot, from being pressed in . This way, once mation to the interlens shutters and which grips onto the camera's film­ you release the shutter there is no way the lens units return the compliment crank attaching pin once the crank to remove the lens aCCidentally. by "telling" the camera its maximum has been removed. This optional film­ 15. Shutter-speed resistors: Nor­ and set apertures. All these pieces of advancing grip is definitely more con­ mally, the marked speeds of a leaf information are exchanged via con­ venient than the crank normally found shutter are controlled within the shut­ tacts within the bayonet lens mount on medium-format SLRs. When you ter unit. Therefore, you have to set (12), and transferred to the AE finder consider that the grip it's attached to your chosen shutter speed on a dial (not shown) via contacts in front of also helps you aim and steady the located somewhere on the lens bar­ the finder screen. camera, it's easy to understand why rel. One drawback of such a shutter­ You might now conclude that. relatively few ETR's are sold without speed control system is that each lens Bronica's clever information transfer this novel accessory. has a separate shutter-speed govern­ system has solved all the major prob­ And that's not all. Bronica's Speed ing system unit, and as you change lems encountered with leaf-shutter Grip incorporates its own angled lenses each shutter will therefore pro­ SLRs. Unfortunately, the one diffi­ Shutter-release button that falls nicely vide slightly different actual speeds. culty remaining is quite a large and under your right index finger. As you To avoid this difficulty Bronica chose sticky one-namely the shutter-cock­ press the shutter button on the speed a centralized shutter-speed control ing mechanism. As you can see in the grip (see the simplified drawing on system. Each shutter unit in each sep­ simplified drawing (page 106), four page 104), a long lever pushed cres­ arate lens barrel consists only of shut­ long, squared-off pins pass through cent-shaped lever (h) clockwise. This ter blades and activating springs. The the lens barrel, connecting the lens­ lever transfers the mechanism's di­ electronic, speed-determination com­ mount section with the shutter unit at rection of motion 90 ° , pushing the ponents are solidly built into the cam­ the front (m). The length of these pins thin rod (i) inward through the base of era body. limits the extension of the lens barrel the grip. Most interestingly, this rod (i) The speeds themselves are con­ and determines its size too. doesn't contact the shutter-release trolled by an electronic device known Bronica's engineers are not the mechanism (right behind the shutter as a timing circuit. This circuit is nor­ only camera designers to have been button on the camera body 10) mally a combination of resistors and working on this age-old problem . directly. Instead, it presses against a condensers which are less vulnerable ('s engineers have finally solved short pin in the bottom of the camera to temperature changes and aging it in large measure in their ali-elec­ body, turning the short lever U) clock­ than their mechanical counterparts. tronic Rollei SLX. We'll let you in on wise. This movement in turn rotates Another advantage of this type of how they did it in a future report.) the shutter-mechanism release lever control system is that additional con­ As you can see from the above de­ (k) in a clockwise direction which trol systems (for example, an auto­ scriptions, Bronica's engineers causes the sliding bar (d) to slide matic-exposure metering system) can created the ETR from scratch and in­ downwards. Thus, the ETR's entire be later added without too much diffi­ corporated many novel concepts int~ shutter-cocking mechanism actually culty. Mechanical timing systems can­ its design. However, they were not reverses directions to release the not have their capabilities extended afraid to ml. -