So you win the Mega Powerball what 35mm SLR would you bring back? Ower

[Lee Rust]

I've always been intrigued by the rotary shutter in my Mercury II half-frame 35... Speeds from 1/20 thru 1/1000... fairly quiet... easy to work on... made from stamped steel... not too many parts. The shutter disc does make the camera design a little awkward and it would be even more so if the disc diameter had to be sized for full-frame. Still, the Mercury was made over 70 years ago by average American workers in the good old USA and my example works perfectly after a bit of cleaning and a few drops of oil.

 

[Paul Howell]

Same with the Argus C3 and C4 shutter, I think it's a similar design.

 

[Donald Qualls]

The rotary shutter in the Mercury was a very different animal -- it was a full disk near the focal plane. A "rotary" shutter in a Brownie or Shur-Shot is "rotary" as in the main shutter disk rotates for exposure, of itself isn't variable in speed (which is determined by the strength of the drive spring, the mass of the disk, and the size of the hole). I don't think I've seen an Argus shutter out of the camera or opened up, but I was pretty sure it was a conventional multi-leaf shutter, overall similar to a Compur (if somewhat simpler).

 

[Wallendo]

A Nikon F4 that has the weight and form factor of an FE.

 

[Sirius Glass]

I would invest and build 6x6 digital 200+ megabit back for the Hasselblad that could handle the SWC and 30mm Fisheye lens properly.

 

[Paul Howell]

35mm and film only, please.

 

[Helge]

I've had some ideas recently for a multi-speed all-mechanical shutter that could be built with the same technology that was used for the (still operating after 50-100 years) rotary shutters used in generations of box cameras (and modern Holgas). Stamped sheet metal moving parts, simple hairpin type springs, and ought to be able to get speeds from 1/15 to 1/200 plus B with only about 2-3 times the total part count of a Brownie shutter. Problem is, I've got no money and little free time to even try to build a prototype.

Is that really a rotary shutter? Isn’t it just a single leaf shutter?
Sounds intriguing though. Want to share some details?
Two leaf shutters that doubled as aperture was (and probably is) quite common. Trip 35 is one famous example.
Apertures could be square or the strange starshape used by among others Konica.

 

[Donald Qualls]

Is that really a rotary shutter?

It's not, and I didn't call it that. I said it could be made with the same technology as rotary shutters, i.e. stamping, shearing, and fine wire torsion springs.

The idea is close to the guillotine type shutters found in Minox and Minolta 16 subminiature cameras, but without the complexity of a pallet and cam timer (those essentially use the same mechanism as a Compur to control the release of the two plates). My idea would use plates with notches, one graduated at different positions (different insertion depths of the control bar would select different notch positions). When the shutter prefires, the leaves release against the control bar, which is then withdrawn for final firing (there needs to be a delay of about 1/100 to let the second plate rest on the selected notch), and the two leaves start to travel -- at the same speed, but from different starting positions, effectively giving a controllable slit width. This wouldn't work for speeds slower than about 1/25 or 1/15 (depending on the actual travel speed of the plates).

Add some simple electronics and you could have timed speeds to several seconds with no additional mechanical complexity, but the original idea was for an all-mechanical shutter that could be mass produced cheaply. Based on the performance of Minox and Kiev 30, it should be possible to get speeds up to 1/500 with this setup, though few modern photographers really need to go beyond 1/250. Electronic timing (directly controlling the release of the plates) might allow not only longer shutter times, but shorter (down to 1/1000, anyway).

 

[Lee Rust]

This is an intriguing idea. Shutter speeds between 1/25 and 1/250 would be sufficient for most situations.

 

[Donald Qualls]

Shutter speeds between 1/25 and 1/250 would be sufficient for most situations.

Oh, yes. There were a lot of triplet-lens family folders sold with shutters that only had 25, 50, and 100 (you'd almost certainly want 200 or 250 now with the commonness of ISO 400 film), but full range aperture (f/6.3 down to f/32 on 6x9, commonly, but for 35 mm you'd probably want to stick with f/3.5 or so down to f/16 or at smallest f/22). Waterhouse stops or V-notches (which give a square aperture, as on lots of cameras that combine shutter and aperture) would cover a good aperture range with minimum parts count and manufacturing cost. Scale focus if you can't make an affordable RF, or offer two models at different prices.

 

[Lee Rust]

So the two shutter plates would swivel rather than slide as in the Minolta shutters etc?

 

[Helge]

It's not, and I didn't call it that. I said it could be made with the same technology as rotary shutters, i.e. stamping, shearing, and fine wire torsion springs.

The idea is close to the guillotine type shutters found in Minox and Minolta 16 subminiature cameras, but without the complexity of a pallet and cam timer (those essentially use the same mechanism as a Compur to control the release of the two plates). My idea would use plates with notches, one graduated at different positions (different insertion depths of the control bar would select different notch positions). When the shutter prefires, the leaves release against the control bar, which is then withdrawn for final firing (there needs to be a delay of about 1/100 to let the second plate rest on the selected notch), and the two leaves start to travel -- at the same speed, but from different starting positions, effectively giving a controllable slit width. This wouldn't work for speeds slower than about 1/25 or 1/15 (depending on the actual travel speed of the plates).

Add some simple electronics and you could have timed speeds to several seconds with no additional mechanical complexity, but the original idea was for an all-mechanical shutter that could be mass produced cheaply. Based on the performance of Minox and Kiev 30, it should be possible to get speeds up to 1/500 with this setup, though few modern photographers really need to go beyond 1/250. Electronic timing (directly controlling the release of the plates) might allow not only longer shutter times, but shorter (down to 1/1000, anyway).

I too have a difficult time visualising what you mean.
Is it like two wings hinged on the same point, locked and with a variable distance slit between them that scans the aperture?

Problem with a guillotine shutter, put between lens elements, especially on large formats and with any kind of DoF, is that is results in jagged, square bokeh.

Some kind of electronically controlled two leaf shutter, would be better and cheaper I think. A simple voice coil mechanism would allow just about any speed you could want, and be very reliable. Perhaps with a big slow blinder shutter in front to lessen requirements on absolute light tightness of the real shutter, lessening that engineering challenge.

For a camera with a big front panel, Waterhouse stops would make very good sense though.

 

[Donald Qualls]

We're talking about a 35 mm SLR resurrection, though, aren't we? You could mount a Minolta/Minox style horizontal guillotine shutter between film chambers at the focal plane, and have room for a mirror box and lens mount (you'd sell it with user-configurable lens mounts so the user could select, say, M42, Nikon F, Minolta or Yashica in the same pre-autofocus age range -- so long as you make the mirror box short enough to accommodate the shortest flange to film distance). You might need to make the camera a little wider than the more compact original cameras, but being able to make a shutter that doesn't require a mad clockmaker to assemble would make it worthwhile. This might even be possible to offer as a kit, similar in concept to the Konstructor from Lomography.

No, not two wings. Look at the shutters in Minolta 16, 16II, Kiev Vega, 30, and 303, or a Minox. Basically a focal plane shutter with solid metal curtains, except those cameras mount it in front of the lens, making it a guillotine type. I'm looking at a much simpler way to time the leaves, but you'd still have a separate aperture so your bokeh would be whatever the aperture created (if you build it to use existing lenses, you'd get the regular multi-leaf iris). I agree, the shutter/aperture combination with a square opening does create ugly bokeh, but this isn't that (that was an alternative, and would be much harder -- maybe impossible -- to implement without electronics).

 

[drmoss_ca]

From the patent diagram for the Pen F, I believe the rotary shutter there is really a half disk that rotates to cover or expose the film gate. The varying speeds are attained by varying the spring tension that drives the disk:

There is a summary of the design process in a lecture by Mr Maitani: https://www.olympus-global.com/technology/museum/lecture/vol1_04/

 

[Andrew O'Neill]

Well, I didn't win Lotto Max up here, so the F3 will have to wait...

 

[Donald Qualls]

From the patent diagram for the Pen F, I believe the rotary shutter there is really a half disk that rotates to cover or expose the film gate

I wonder if that isn't approximately the same method used by the Univex Mercury? It would certainly be more in reach than varying a slit width on a rotary disk (basically requiring two disks that lock together at multiple included angles). Most commonly, however, that leads to the infamous, hard to design, fabricate, and maintain pallet delay to get slow speeds.

 

[Helge]

We're talking about a 35 mm SLR resurrection, though, aren't we? You could mount a Minolta/Minox style horizontal guillotine shutter between film chambers at the focal plane, and have room for a mirror box and lens mount (you'd sell it with user-configurable lens mounts so the user could select, say, M42, Nikon F, Minolta or Yashica in the same pre-autofocus age range -- so long as you make the mirror box short enough to accommodate the shortest flange to film distance). You might need to make the camera a little wider than the more compact original cameras, but being able to make a shutter that doesn't require a mad clockmaker to assemble would make it worthwhile. This might even be possible to offer as a kit, similar in concept to the Konstructor from Lomography.

No, not two wings. Look at the shutters in Minolta 16, 16II, Kiev Vega, 30, and 303, or a Minox. Basically a focal plane shutter with solid metal curtains, except those cameras mount it in front of the lens, making it a guillotine type. I'm looking at a much simpler way to time the leaves, but you'd still have a separate aperture so your bokeh would be whatever the aperture created (if you build it to use existing lenses, you'd get the regular multi-leaf iris). I agree, the shutter/aperture combination with a square opening does create ugly bokeh, but this isn't that (that was an alternative, and would be much harder -- maybe impossible -- to implement without electronics).

Good ideas don’t often scale.
What works on micro cameras becomes unwieldy and too big when scaled.
Stiff shutter blade(s) that covers the whole of the film gate will necessitate a much wider or taller camera than anyone is willing to accept and pay for, now that they know it’s possible not to have it.

Simplifying rolling curtains (modern material must surely be able to help here) or a better box shutter would probably be a better bet.

 

[Lee Rust]

The Mercury shutter always rotates at the same speed with a variable sector width to determine exposure.

 

[Helge]

The Mercury shutter always rotates at the same speed with a variable slit width to determine exposure.

I wonder why they didn’t just go with a simple leaf shutter?

 

[Lee Rust]

I think the design objective was to reliably achieve 1/1000 second with a mechanism that was fairly easy to manufacture with average labor skills.

 

[Helge]

I think the design objective was to reliably achieve 1/1000 second with a mechanism that was fairly easy to manufacture with average labor skills.

Yeah, but why? With speed of common film back in the day 1000 speed would not come in handy very often.

 

[Donald Qualls]

Yeah, but why? With speed of common film back in the day 1000 speed would not come in handy very often.

Same question with the 1/1000 capability on a Speed Graphic's focal plane shutter.

Answer is: if you can shoot at f/8 or wider, you can use 1/1000 to freeze motion with even fairly slow film (in Sunny 16 conditions, 1/1000 on ASA 100 would only need f/8 or so).

Beyond that, people (Weegee) sometimes used HUGE flashbulbs, fairly close up (say, inside 10 feet) and a fast shutter to get the same effect with slower film.

 

[Pitotshock]

I like the idea of a Nikon F6(F7) with updated focus technology and the capability to use the newer lenses with the magnetic diaphragm aperture design.

How about IBIS technology applied to the film???

 

[abruzzi]

How about IBIS technology applied to the film???

that’s an awful lot of mass to move around—it would have to be the film cassette, the take up spool, and all of the camera body that holds that in place. I know Contax did an auto-focus mechanism, by moving the film closer or further, but I don’t know if it moved the whole film path (probably) or it it was fast enough to use a similar mechanism to do IBIS (probably not). But it’s certainly an interesting idea.

 

[Helge]

that’s an awful lot of mass to move around—it would have to be the film cassette, the take up spool, and all of the camera body that holds that in place. I know Contax did an auto-focus mechanism, by moving the film closer or further, but I don’t know if it moved the whole film path (probably) or it it was fast enough to use a similar mechanism to do IBIS (probably not). But it’s certainly an interesting idea.

It’s would be fairly easy to grasp the film firmly in a frame and move that around, using films ability to bend. We are talking very small movements after all.
Also sucking or pressing film into a gentle curve under a lens element would allow smaller, simpler and better wides.