Stretching Fibre Optic trigger cables

[shanesmith.photos 13]

Hi all,

I've recently been noticing that my strobes intermitently fail to fire if I fully extend my strobe arms (for big scene wide angle shots), stretching the coiled fibre optic trigger cables. Once I pull the strobes a little closer to the housing body (reducing the stretch) they seem to return to their normal reliable selves.

Is this normal behaviour that other people experience as well, or might I need to get some new or longer/different cables? Could the stretch on the cables somehow be reducing the amount of light they transmit, or is this a red herring? My strobe triggering used to be utterly reliable, but more recently seems to be a little hit and miss.

Details about the gear:
I'm using a pair of Nauticam's universal fibre optic cables, Retra Pro X's and a Turtle Smart TTL strobe trigger (on a full frame Sony camera). For each strobe I'm using a 250mm float arm + a 200mm (normal) arm, so 45-50cm combined when fully extended. Nauticam's website says that the underlying cables are 1m long before coiling, so this doesn't seem like an unreasonable degree of stretch. The fibre optic cables always return to their normal compact coiled shape after use, so I'm not stretching them so much that they permanently deform.

Thanks,

Shane

[TimG 62]

Hi Shane

It could be the stretching or, I suspect slightly more likely, the pull is taking the fibre cable away from the centre of the strobe sensor - taking it off-centre. This can cause misfires and, from my own experience, it can certainly reduce TTL capability (I've got Retra Pro X too).

I'd suggest firing the strobes on land with the cables but under no tension. If you get 100% success then add a tension on the cables and see what happens.

I don't like the twisted cables for exactly the reasons you set out. In the end I made my own which is pretty easy and WAY cheaper than the bought ones. There are a number of threads about this. Just cut the cables with a very sharp knife (eg a box cutter or Stanley knife) to cut a flat edge. I initially cut the cables with scissors. Worked perfectly with the Retras on Manual - but not TTL!

 

[shanesmith.photos 13]

Ah, that’s a more plausible explanation! Thanks for the idea. I’ll give that a try.

[TimG 62]

No worries

If you've not found it already, this might be worth  read:

 

[Pavel Kolpakov 74]

When the era of optical cables (especially those with multi-fiber core) in underwater photography began, we were all excited about this new way of synchronization that replaced electric cables. The benefits were immediately obvious. Much later came the realization of new problems. The most significant problem manifested itself with spirals. During production, these optical cables are twisted into a spiral of a rather small bending radius, then the spiral is heated at high temperature and then retains its shape. During this heat treatment, the fibers become brittle. Further, during the longtime operation, with repeated stretching, the fibers break, the cable partially loses the transmission coefficient or completely loses its performance. So, we are forced to change the best FO cables from time to time, this is reality.

Edited October 9, 2022 by Pavel Kolpakov

[TimG 62]

14 minutes ago, Pavel Kolpakov said:

Much later came the realization of new problems.

Totally agree, Pavel. And problems which can be surprising too.

But, for me, the advantages of fibre still far outweigh electrical connections in their ease of use, replaceability, price and convenience. Not to mention off-housing shooting.

[Draq 111]

For those who do not make their own fiber optic flash cables, is there any reason not to use the Howshot 613 cables, which are quite a bit less expensive than the S&S and Nauticam cables?

https://www.divervision.com/howshot-fiber-optic-cable-613l-for-dualys-connector-OFL613-SS-SS.html?search=613 fiber

https://www.backscatter.com/Sea-and-Sea-Fiber-Optic-Cable-II-M2-Medium-18

 

[davehicks 89]

Divervision seems to have some good prices on cables. If it's what it says it is, then it should be good. Let us know how they work out.

 

[Pavel Kolpakov 74]

2 hours ago, Draq said:

For those who do not make their own fiber optic flash cables, is there any reason not to use the Howshot 613 cables 

Most manufacturers of 613 type cables now use 613-fiber produced by Japanese company Asahi Kasei. But thermo coiling technology is different a little bit (basically, this is what affects the life time of the cable), also different connectors, cable length, price etc. So, there is some choice now.

Edited October 9, 2022 by Pavel Kolpakov

[Pavel Kolpakov 74]

4 hours ago, TimG said:

But, for me, the advantages of fibre still far outweigh electrical connections in their ease of use, replaceability, price and convenience.

I absolutely agree with you Tim. Optical fibers are much better for underwater usage anyway. Electric sync cords gradually becoming a thing of the past.

Edited October 9, 2022 by Pavel Kolpakov

[Draq 111]

My current cables are working fine, but I like to carry spares on the assumption I will have one fail or get lost.  It is worth a little more $ to me get better cables with a longer likely lifespan, if there is a meaningful difference, but I have no way of knowing about the different manufacturer's coiling technology.   

[TimG 62]

On 10/9/2022 at 1:55 PM, Draq said:

but I have no way of knowing about the different manufacturer's coiling technology.   

Just don't buy coiled ones. From my experience with them, there is so little benefit.  Just get straight ones based on the maximum length of your strobe arms. It's easy enough to create a pathway for them using rubber bands, tie-wraps or sticky tape (!) if you have to guide them around arms/buoyancy/clamps/whatever.

[Draq 111]

I have looked, but I have been unable to find pre-assembled flash cables that are not coiled.  I think I was able to purchase them back several years ago, but cannot find them now.  I know, I should just make something myself, but I am lazy.

In truth, I have had few problems with the coiled cables int he past, especially if i get the longer length, so there is less stress on the coiled bits.

[TimG 62]

14 minutes ago, Draq said:

I have looked, but I have been unable to find pre-assembled flash cables that are not coiled.  I think I was able to purchase them back several years ago, but cannot find them now.  I know, I should just make something myself, but I am lazy.

In truth, I have had few problems with the coiled cables int he past, especially if i get the longer length, so there is less stress on the coiled bits.

I'm so tempted to offer to make you some - but getting the all the bits to Sint Maarten is a darned sight harder than making them! Putting them together is less than a 10 minute job and weirdly satisfying given how little it costs.

How about these? https://www.divervision.com/deeproof-straight-fiber-optic-cable-sof?search=fiber optic&page=2

[Draq 111]

1 minute ago, TimG said:

How about these? https://www.divervision.com/deeproof-straight-fiber-optic-cable-sof?search=fiber optic&page=2

I saw those but could not tell what kind of core they use.  You are probably right and I should just make some.  I have switched connectors between cables before and I suspect that I can probably cut them right so no big deal.

[TimG 62]

1 hour ago, Draq said:

You are probably right and I should just make some

Yeah, it's really no big deal: Howshot connectors from Divervision, 613 strand cable from Industrial Fiber Optics, Inc (613-core Fused Multi-core Simplex Cable, Polyethylene Jacket- MCQ-1000 ) for $7.50/metre.... a cutting board, a box-cutter, eye-glasses size screwdriver to screw the two halves of the Howshot connectors together - and Bob's your uncle. 

Cost = Small;

Time = Minimal;

Satisfaction = Massive:  

...... and you end up with the exact cables you want.  

Adaptors: https://www.divervision.com/howshot-fiber-adapter-l-for-seasea-ys-strobes-FAL-SS.html

Cable: https://i-fiberoptics.com/asahi-multi-core-cable-detail.php?id=3358&sum=166

[Draq 111]

Ok, I am convinced.  I will order parts and "build" a couple cables.  Thank you.

[TimG 62]

28 minutes ago, Draq said:

Ok, I am convinced.  I will order parts and "build" a couple cables.  Thank you.

Yay! Good man. Let us know how you get on. 

[Barmaglot 223]

On 10/9/2022 at 10:01 PM, Draq said:

For those who do not make their own fiber optic flash cables, is there any reason not to use the Howshot 613 cables, which are quite a bit less expensive than the S&S and Nauticam cables?

I've been using those for a while now, no issues triggering strobes (SeaFrogs and Retra) with either on-camera flash or UWT trigger, but I did have one break near the connector - I snipped off the end, disassembled the connector and reattached it on the new end; no problems after that. I've been told Sea & Sea cables are more robust, but don't have personal experience with them.