View Full Version : Question about a Topcon Dual Cable Release

tom thomas
18-Nov-2008, 17:07
I picked one of these up thinking I could use it to do side by side testing of various TLR's but am now wondering if it actually isn't intended for LF camera use.

It's a Topcon/Japan dual release, heavy duty with instant release and lock for time exposures. Quite a throw on the plungers. They are both adjustable for independent throw lengths too. It's about 20 inches from plunger to tips.

I tried googling it but other than a few offered for sale by different vendors, can't find out what it was used for normally.

Were these things used on the LF cameras?

Tom Thomas

Dan Fromm
18-Nov-2008, 17:53
Tom, I doubt it.

The shutters used on most LF cameras accept just one cable. Major exceptions were the Prontor and Copal #1 Press shutters used on Polaroid MP-3 (Prontor, mainly) and MP-4 (Copal, mainly). These accept one release cable to open the shutter for focusing (it holds the shutter open while pressed) and another that fires the shutter when pressed. The shutter won't let both be pressed simultaneously. I've seen MP-3 Prontors with two cable releases attached. The snag with using a dual cable release like yours on such a Prontor is that both of the cables press when the button is pushed, and that's not the way to operate the shutter.

I have an Olympus dual cable release that I sometimes use with a Nikon (one of the cables fires it) and a MicroNikkor (reversed if necessary) plus BR-4 ring (the other cable stops the lens down) on bellows. I believe, can't prove, that all of major 35 mm SLR systems have similar devices. They allow focusing at full aperture and stop the lens down to shooting aperture while firing the body.



Nathan Potter
18-Nov-2008, 19:44
The 35mm Nikon systems I used for macrophotography utilized double cable releases for extension bellows operation. The lens end of the bellows was not cammed to the camera. A single plunger in ones hand first actuated the stop on the lens then fired the shutter on the camera. The two plungers were simply of different lengths. Exactly as Dan describes above. I've seen the Olympus unit that Dan mentioned above but never seen any others for 35mm use.

Nate Potter, Winter Harbor Me.

Robert A. Zeichner
18-Nov-2008, 20:00
These were quite common for use with Leica RF cameras with the Visoflex attachment, a device for being able to view through the taking lens like an SLR. One release actuated the mirror flip up assembly and the other, the shutter release. There were a couple of types depending on vintage. I think I still have one of these.

tom thomas
18-Nov-2008, 20:18
thanx for the replies guys. The release has such a long (20mm) but adjustable throw (abt 18mm) that I'll have to be very careful if I use it with Rollei's and Yashicas I want to test lens quality with side by side simultaneous shots.

Should be fun trying but probably should rig up a double unit with the ones recommended instead of this one. Don't want to jam the shutter mechanisms with it.

Tom Thomas

tom thomas
19-Nov-2008, 14:54
Just thot I'd post a photo of it in case someone recognizes it and it's usage. I'd also found some mention of the dual release on old Nikon's but no photos so wasn't sure if this a Topcon version for it.

Tom Thomas

Bob Salomon
19-Nov-2008, 16:10
Way back when, I was the Product MAnager for the Besler Topcon Super D which this was an accessory for. It, as well as others from Nikon, etc. were for automating the aperture when the lenses were used on accessories like bellows and extension tubes.

Double and even triple releases were fairly common up until a few years ago. Kaiser was one of the last companies to offer one. Theirs came with 2 cables and a third was available as an accessory.

The reason they were adjustable for throw was to make sure that the timing between activating the shutter and the lens closing to the correct aperture was correct. Otherwise the shutter might have fired before or after the lens was at taking aperture.

Dan Fromm
19-Nov-2008, 17:32
Tom, thanks for posting a picture of yours. It looks very much like my Oly cable. I wouldn't be surprised if both had come from the same small machine shop.

Now that I think of it, the good Topcon reflexes used Exakta mount and some lenses for Exaktas had external diaphragm automation. A shutter release button on the lens barrel stopped the lens down and then pressed on the body's front shutter release to fire the shutter. A dual cable release preserved diaphragm automation when the lens was on tubes or bellows.

Using a dual cable release to synchronize cameras for stereo isn't a new idea, but I've never heard of it being done for lens testing.



Jim Galli
19-Nov-2008, 17:48
I think they also made some of these much older than this one back in the days when shutters didn't have sychro for flash. One would trip your shutter while the other fired your flash bulbs. This would also require some synchronisation which would account for an adjustment possible at the threaded end.

tom thomas
19-Nov-2008, 18:04
Thanx for the info guys. Bob, thank you too for the exact Topcon model. Now I can google it to read up on how it was used.

It sure is a beautiful made product. Gleaming chrome and very well finished.

I'd thought it was a single release with a spare. Just kidding

Tom Thomas.