Cable Releases - who makes custom versions

[bglick]

Does anyone know who makes custom cable releases?
I have searched quite extensively, but can't seem to find a source...of course the big makers are not interested in making a couple of anything, so I need a cable craftsmen... TYIA

[Dan Jolicoeur]

Not sure what you are looking for that can't already be bought but, You may want to check a high end custom Bicycle shop. A technician that makes cables for gears and brakes mybe able to make a custom cable?
Just a thought,

[bglick]

Dan, that is a good idea, never thought of bicycle gear....... the purpose is, to fire two lenses for a synced stereo pair.

I am trying to have one Copal shutter drive another Copal shutter, simulatneously. I put a normal cable release into the first shutter, so when it fires, a cable assembly attatched to the rear of the first shutter fires the second shutter.

Mechanical linkage is not possible due to the location of the two hammers. A dual cable release is not ideal, as the slightest change in position of the cables causes the timing to differ......hence why I need a fixed cable connection between the two shutters.

[Bob Salomon]

We make OEM releases. Send us a drawing we can send to the factory and we can see if your requirement can be done. We make releases that push as well as pull.

[Norbert Gruetzner]

Bill, how about taking a pneumatic driven cable release. (I don`t know how you call these in english, in german its e.g. Hama Pneu Ausloeser). You can easily prolong these ones or make linkings. The air pressure should automatically fire both shutters.

Greetings from Bonn

Norbert

[John_4185]

Just curious, but what are you trying to get that is not already made?

[Wilbur Wong]

How close in timing are you trying to achieve? Are you shooting a moving subject?

[ronald moravec]

Sound trigger on each might work. Also light synced like those for wildlife photography.

[bglick]

Thank you for the input....

Bob, I actually have no drawing yet, I simply have two Copal 0 shutters that are assembled on a single lens board, with lens centers only 73mm apart. The shutter hammers are faced away from each other, hence why I am trying to come up with a permanent cable assembly, between the two. Then I fire just one with a normal, screw-in cable release. However, there is other possiblities...for example, you mentioned, pull cables.... if we can pull each cable, then its possible we can pull the hammers back, instead of pushing it. Not sure if there is an advantage to this.

Acutally, syncing two copal shutters, assuming new and in good condition, is relatively easy, as they are very consistent in their mechanical workings. I have synced them with standard dual cable releases up to their max. of 1/500th second, but this is not a permanent solution as you have to adust the cable screw-in adjustment each time (which works very well) till the lenses sync. However, then, the smallest movements of the cables, changes the throw feed rate of each cable, loosing sync. The cable path is very sensitive. Hence why I need a permanent solution which is permanetly attatched to the lens board, never to be removed. Then I will simply screw in a standard cable release to fire one shutter, or into a block, which has 2 cables that fire both shutters....

A simple solution is two short cables (approx. 8") which have plungers on both their ends. One end would screw into the shutter as normal. The other end into a machined metal block, permanetly affixed to the lens board. The machined block will accept a standard cable release to initiate the action. This master cable release will push a single bar inside the block. The bottom of this bar will will push both plungers to fire each shutter. The plunger itself will be pushed by recessed screws in the bar. By adjusting these screws, it varies the individual timing of each plunger till lens sync is acheived.

Bob, if you have a source for this, I can make a drawign and email it to you? Please advise...



As for pneumatic, its possible, but just like air solenoids, the weakness is often the solenoid itself. I have tested several of them, and they cause way too much motion / vibration when the solenoid engages. Mechanical cable releases are quite nice for this purpose, hence their use for 150 years. All the bits and pieces needed to accomplish this currently exist, (except the block, which I can have made) but, not in the lengths and sizes I need them.

[John_4185]

www.rmm3d.com/shooting/twin-release.jpg (http://www.rmm3d.com/shooting/twin-release.jpg)

www.berezin.com/3d/dual_cable_release.htm (http://www.berezin.com/3d/dual_cable_release.htm)

and many more like those are available

[bglick]

jj, not sure if our posts crossed paths... but I described in detail above why these products, which I own them all, are all toublesome for long term, permament, consistent, lens syncing....

Thanks

[John_4185]

Okay. Thanks, Bill. I lost track of the thread.

For great precision I would think that to make them both trip so that top speeds would synch would require that one go beyond the cable activation mechanism. Tiny electric solenoids with zero travel... dunno. Maybe RC airplane gizmos would suffice.

[Bob Salomon]

Bill,

The factory that makes our Gepe releases can make custom ones for industrial and scientific applications. There would be a couple of problems. The first being that 1 up production is not very cost effective. The second is are the springs in a Copal shutter strong enough for one shutter to fire the other at all shutter speeds.

In theory what you are trying to do is take a Gepe Wide Angle Extension type release and somehow attach it to both shutters to fire them at about the same time.

The easy way to do this would be with a pair of Rollei Linear Motor Shutters as these are fired electronically.

[bglick]

I should have mentioned....

Electronic shutters from Rollei, Schneider and the such are too wide.... I can not maintain the center lens spacing....

Bob, do you think you can have the cables made as i described above? Just simple plungers on both ends? Or do you know a source for such?

[Bob Salomon]

We would have to give the factory specs and drawings.

[jantman]

Bill,

Three thoughts-

1) a smaller electronic shutter?
2) A pneumatic (air) release, such as those giant expensive ones that have been discussed here before
3) How about somehow fitting a set of servos to either the shutter trip levers or to the cable release sockets? It would be a custom construction of simple servos, which would be tripped by a controlled power source. Perhaps servos of the type used in model planes/cars/etc.?

Is it possible to modify the camera itself to make this whole job easier?

[John_4185]

http://elearning.winona.edu/staff_o/jjs/tmp.gif

For starters, are your shutters set up like this? Maybe from here we can get a better idea of what you have and need.

[bglick]

1) a smaller electronic shutter?

I have searched the planet, can not find any...and the ones I do find, which are too wide anyway, are also way to slow, max. speeds 1/60th.... Horseman, Rollei, Schneider, etc. but if anyone know of any that might work, I am all ears....

2) A pneumatic (air) release, such as those giant expensive ones that have been discussed here before

Air has great potential, but the solenoid has too much kick, thereby using two of them produces way to much vibration, as I am going after very sharp images....

3) How about somehow fitting a set of servos to either the shutter trip levers or to the cable release sockets? It would be a custom construction of simple servos, which would be tripped by a controlled power source. Perhaps servos of the type used in model planes/cars/etc.?

I explored this also....and Fuji makes servos that fire Copal shutters on their 6x17, but they are big, cumbersome, and once again, too much vibration, specially two of them...

> Is it possible to modify the camera itself to make this whole job easier?

I haven't even built the camera yet, so I can modify anything.... but we still have two lenses about 73mm apart which limits the positioning of the lenses as they have many moving levers outside their circumfrence.

jj, this arrangement will not work, as the levers stick out too far..... here is the best set up I can think of....

The right lens, looking at the front element, will have its PC socket at 1 o'clock. The same with the left lens, 1 o'clock. This provides the proper gap between the lenses whereas none of the external leves will bang the other lens...so as you can see the two shutter hammers are far from each other, hence why cables are well suited as they can be wrapped around to accomodate the awkward hammer positions.

[bglick]

Actually, the PC socket is closer to the 12 o'clock position.......

[John_4185]

http://elearning.winona.edu/staff_o/jjs/sketch1.gif

Just a sketch. What is not shown is the little solenoid and shaft behind and inbetween the lenses that turns the cam. It would have a manual mode for composing.

If you haven't built it yet, then perhaps you could arrange the lenses thus. This is not a new idea. These cams, rods and swivels are common stuff, and since last night when Ernest helped out on my odd shutter, I know more about solenoids than I like. (They can be driven with small batteries.)

Very smooth, too.

[Struan Gray]

www.uniblitz.com

[bglick]

jj, that is quite an impressive arrangement.... is this just a drawing, or something you actually did?

This system will have some issues with sync, as there is no adjustment method between the two rods, other then filing them down, but this is a very tedious method, and sometimes not too consistent, but surely, if the solenoid fired fast enough, it might would work.

Do you have a contact for these smooooth solenoids? Most plunger types I have seen are quite mecahnical and use too much force....as you need force to fire quickly, this is the secret to sync...but then, in a solenoid, there needs to be a "stop" for this force, and its that stop that creates vibration. In your case, you are using a rotating solenoid, quite different.... If it wasn't for the tight lens spacing I need to maintain, I am sure mechanical linkage would be best....

[bglick]

Struan, nice to hear from you....

I spoke with UniBlitz at length, and they have NOTHING that will work.... everything is either huge or too slow.... and NO LCD shutter will suffice, I thoroughly investigated that.... so I think its back to cables, some things never change....

[John_4185]

For adjustment one could simply screw in/out the attachment to the shutter release block. It could be done by adjusting the overall length of the release pins, too. With parts that short, I can't see how it could be less accurate than two cable releases; cables have issues with dimensional stability (stretch, compression) and overall length. More cable, more room for slop. See how they work and it should be clear.

Solenoids, thanks to Ernest, see: w2s.ledex.com/ledx/ds/lx000/lx0002e.lasso?pcode=L229 (http://w2s.ledex.com/ledx/ds/lx000/lx0002e.lasso?pcode=L229) mine is model 3B.

Here's the highlights of these models. First, they have a constant total-throw speed. Common electromechanical models speed up and throw harder as they go through the stroke; these do not. See the points in the PDF regarding the three-ball speed control. Second, the stop yes, you can order them in various limitations of throw (30,45,90 degree) so you don't plunge through your delicate parts. (Of course, you can vary this to accuracy within a degree in the actual build.) Third, they come in various torques. Clockwise, Counter-Clockwise, different thicknesses, spring tensions, the whole nine yards.

There are other solenoids, too.

Here's on a shot the shutter that led Ernest to point me in the direction of Ledex brand hardware from another thread here elearning.winona.edu/staff_o/jjs/shutter.jpg (http://elearning.winona.edu/staff_o/jjs/shutter.jpg). That is the Ledex 3B, 45 degree, CCW model from a spendy research LF camera.

[bglick]

> For adjustment one could simply screw in/out the attachment to the shutter release block. It could be done by adjusting the overall length of the release pins, too. With parts that short, I can't see how it could be less accurate than two cable releases; cables have issues with dimensional stability (stretch, compression) and overall length. More cable, more room for slop. See how they work and it should be clear.

I agree in principle here...cables are not perfect ..... But their imperfections can easily be tuned with an threaded adjustment, this makes for a nice feature in the field. In the past, I have done quite well with make-shift cable arrangements, but for this camera, I want a permanent solution....

It is possible, a solenoid could do the job, but my problem is physical contraints. I can NOT put the solenoid directly into the cable release thread, as there is not enough space, as it is sitting atop a Schneider helical focussing ring. So the solenoid would have to be attatched to something, such as a cable, to access the hammer. In which case, if I am back to cables, I might as well, just use ONLY cables, make sense? Plus, cables are fail proof, require no power, no motors to fail, etc.......

You certainly have a fair amount of knowledge of this, quite impressive.... it seems, so close, but yet so far for me, I just can't think how these can be utilized effectively....

[John_4185]

It is possible, a solenoid could do the job, but my problem is physical contraints. I can NOT put the solenoid directly into the cable release thread, as there is not enough space, as it is sitting atop a Schneider helical focussing ring.

I'll give it a rest. It is impossible to design something in this manner; can't see what you are doing, the rules change, you know.

[bglick]

jj, I realize this was an odd application, lots of variables to overcome....

I think I just stumbled over the solution...one of my dual cable releases has exactly what I described, dual plungers and an adjustable set screw for one lens...... I will post a picture whenever I successfuly complete this... thanks

[Struan Gray]

I spoke with UniBlitz at length, and they have NOTHING that will work

Ah well. I look forwards to seeing the finished result. And even the photos :-)

One thing that struck me is that unless you are photographing things that move very fast or need to use a small, short-duration flash, it won't realy matter if your two shutters fire a little bit out of sync. How much will it matter if both shutters fire at 1/500, but 1 ms apart?
With most human subjects, or with longer-burn studio flash units, it's not going to be an issue.

[John_4185]

If precision and consistency is your objective, then you are going down the wrong path with cable releases. You will not find two commercial mechanical shutters with (nominal) 1/500th of a second equal. They are simply not that precise, but as Struan suggested, you can get close enough. Finally, if this is a stereo application and if your subject distance s vary, you might eventually find that fixed lens separation is a Bad Thing. But we won't go down that road either.

Sense frustration? I've Yet Another friggin unbearable requisites meeting concerning a 3D application today. The client's sit-on-his-ignorant-ass penchant for precision was fostered in Wonderland and will be evinced in the same: it ain't gonna happen.

[bglick]

> One thing that struck me is that unless you are photographing things that move very fast or need to use a small, short-duration flash, it won't realy matter if your two shutters fire a little bit out of sync. How much will it matter if both shutters fire at 1/500, but 1 ms apart? With most human subjects, or with longer-burn studio flash units, it's not going to be an issue.



Struan, I used to think the same thing.... and although most subjects are not moving that fast, in many cases, you would be amazed what does move fast enough to ruin a stereo scene... an example is bird flying, a tree limb swaying in a breeze, etc. Any tiny bit of difference causes retinal rivalry, specially in the vertical plane, as the eyes have virtually no tolerance for vertical mis alignment.

I measure the shutters, by shining a light through the front elements, then put mirros behind them, so as their light is forced onto a single shutter tester.... i test the lenses first, individualy, then together, this tells me how close the sync is, as if its perfect, the two readings are identical. I have never achieved 100% sync t 1/500th yet, but have not tried hard enough either, but have gotten to 70% sync at 1/500th..... 1/250th is usually 90%+, of course much of this is very sensitive to the shutters you are working with. Of course, I have done much worse also :-)



> If precision and consistency is your objective, then you are going down the wrong path with cable releases. You will not find two commercial mechanical shutters with (nominal) 1/500th of a second equal. They are simply not that precise, but as Struan suggested, you can get close enough.

Well, from past experience, I feel I can get close enough, while not re inventing the wheel here. Trust me, I am open to any new system that would be more effective, but so far, I just can't see anything else being as effective. Except of course, a single focal plane shutter, and I have searched high and low for these, they just don't exist. The older versions from the 50's are too big, clunky, even Linhof abandoned the product.... very difficult. The few companies that make them today, way to slow, and not suited for the format... a nightmare of logistics for the camera.

As per Struans suggestions in a previous post, I tracked down some other focal plane shuttes, that has possibilites for behind the lens shutters, but again, same problem, to big, such as Sinars 6x4.5 fl planes shutters, in addition, they would cause tremendous shake on the lens panel, not to mention, they were only designed to fit with certain backs, so the would have to retrofitted to the point, the cost would probably be $8k per camera.

LCD shutters held the most promise, but these shutters have very limited applications in photography.... technology has not progressed far enough, and may never based on discussions I had with OEM's that develop and build the technology. At best, they will be for studio applications.



> Finally, if this is a stereo application and if your subject distance s vary, you might eventually find that fixed lens separation is a Bad Thing. But we won't go down that road either.

Yes, its best we not go there :-) I literally spent 5 years isolating the problems when separating the taking lenses more then human eye spacing....I have run many tests on many people, and this was the motivating force behind designing / building this stereo camera. I have a pair of Mamiya 7's that sync at 1/500th, yet, they are useless for me.

> Sense frustration? I've Yet Another friggin unbearable requisites meeting concerning a 3D application today. The client's sit-on-his-ignorant-ass penchant for precision was fostered in Wonderland and will be evinced in the same: it ain't gonna happen.

jj, what exactly do you do? Are you a camera builder? Camera repair shop? Designer? I am very curious. Don't rule out cables.... although they have weaknesses, as does everything you try to retrofit for this task, the cables do have some promise. I have found, the key to making cables work, is to affix their position on the lens board, so they have virtually no movement, this is how you gain consistentcy.... then, as for the compression of the cables, this is true, but it must be overcome by a fast thumb throw, so it lessens its effect. To compensate for a fast thumb throw, you must set the throw length of each plunger so it does not push the hammer past the point of fire. This prevents the fast throw speed from rocking the lens.... As you can see, this requires lots of tinkering, but once you get it, it should stay for quite some time, then when something changes, such as one cable compressing more then another, you work the screw in adjustment threads to compensate....so not as eloquent as electronic fire, but workable. Even electronic fire on my M7's can only hold 70% at 1/500th, due to the internal workings of the shutters, as I fire a momentary switch with two poles, so you know they both get identical firing from the switch...but then you must deal with shutter lag.

Its interesting, a company created a product to perform this exact task on smaller digicams....

http://www.berezin.com/3d/Lanc/

This device overcomes the difference in shutter lag between two cameras.... but it only works with digicams that have a special Lanc port, which, is very few, mainly Sony's.

I actually once thought of making a single, large manual shutter that fit over the lens front, attatched with soft material so no shake would transmit from the shutter to the lens... this shutter would be supported by a small mono pod... it would be similar to focal plane shutter, except it would have nothing but a single slit in it.... you push the slide through a consistent pace, which you practice to gain consistentcy. Shutter speed is controlled by the slot size, so you need several slot inserts into the slide. But, this limits many of the possible scenes, unless you always have time to set up, and the consistency of exposure will never be as good as a dedicated shutter, however, you will acheive perfect lens sync everytime. So it fixes one problem, but create a new one..... argggggg....

As you can tell, I have beaten this up pretty good and am quite frustrated I am back to dual cables....





I am still open to any suggestions for methods to accomplish this task....

[Bob Salomon]

"digicams that have a special Lanc port, which, is very few, mainly Sony's."

Canon and Sony use LANC.

[John_4185]

OT: To answer Bill: My regular job is in software development, implementation, R&D and illustration for teaching and learning in higher education. I do some incidental photography for the same.

Bob Salomon is right, of course. Canon uses LANC very nicely; some of their earlier controllers work with later devices, such as the XL-* digital video cameras which I use.

Back On Topic: Enough. It is an unusually beautiful, clear and warm Minnesota morning and I'm headed North in an hour to enjoy it. Last night I just finished refabricating a 360mm lens. Let's see how it works.