Single And Multicore Fiber Optic Cables - Some Practical Points

As Wetpixel members use fiber optic cables and end plugs (adapters) to trigger underwater strobes, I have gathered some practical information about these cables, plugs, and their problems.

Underwater Fiber Optic cables can are single or multi-fiber (strand), coiled or ‘straight’. 

Problem: Breakable Single Fiber Cables of 1 mm diameter, with a thin rubber coating are commonly sold. They are unreliable as the fiber breaks easily. It is important to watch out for, and not buy, them.   

Problem: Coiled cables, single or multi-strand, are a pain as the coil gets in the way, can get caught and lost while diving. As the coil stretches only a little, it is hardly useful. Coiled cables are best avoided.

Some solutions are: 

Make one's own Toslink Cables with Uxcell Plug Ends

A 2017 Wetpixel post by Chrisdarke and others describes how to make one's own fiber optic cables, using Toslink audio cable and Uxcell plugs (1). Both are inexpensive, tough, and readily available on the web, an excellent DIYchoice.

Toslink cable is 3 mm o.d. with a 1.3 mm single light carrying fiber.  Uxcell end plugs are glued to its end. The cable tip can be tapered with a razor blade, like sharpening a pencil, to fit tightly in the plug, then glued with rubber or ABS plumbers cement, and the tip cut with a razor to give a clean end. 
To keep the cable securely out of the way while diving, TimG suggests one weave it through the holes of the ULCS-style arms, where it is easy to remove, with no strain on either plug end (2).

Multistrand Cables.
Multistrand cables may be taking over the fiber optic cable world, as they are tougher and carry more light than single fiber cables. They have multiple fine fibers, from 9 up to 613 light conducting fibers per cable, and cost about $7.50 / meter. An example is the 613 core fiber cable, P/N MCQ-1500-22, made by Asahi Kasei in Japan. One advantage of a multistrand cable is it bends in the right angle of a Hotshot-style L-adaptor (2).
Otherwise, a cable with a high number of fibers is hardly a must for strobe use, as cables with one, or a small number of strands, are also excellent choices to fire uw strobes (2), cost less and are easier to get.

Cable End Plugs
Most strobes and housings use the 7 mm diameter Sea&Sea type plugs (aka adapters or grommets) sold by Fun-In and DiverVision in Taiwan, and Amazon and uw photo stores elsewhere.
The plugs are made of one piece rubber or plastic, with holes for 1.5 mm cable, or are L-shaped, with two halves joined by screws, and a central L-shaped cable groove.  TimG tells us he uses a cable with Howshot L-adaptors at the housing end, and Inon double bush plugs at the Retra end. In his experience, the 613 and 217 core cables both work perfectly (2).

I have used the Uxcell strain relief plugs with Toslink cables for over 4 years to fire my Sea&Sea YS-D2J's and Inon Z240 strobes; these cables and plugs are tough, inexpensive, readily available and have worked perfectly for me, with no problems.

Complete Cables With Plugs
UW photo stores such as Backscatter, Reef Photo, B&H, Amazon and others, including eBay, sell complete cables for prices ranging from $18 to $135 and higher. As far as I can tell, if the buyer’s goal is to buy a reliable, low price, multifiber cable, the price has no relation to quality.
As it is important to avoid single fiber, breakable cables, one has to double check that the seller explicitly states the cable is multi-fiber. Buyer beware.

Suggestions
If you are not inclined to configure your own cable, my suggestion is to buy a low price multi-fiber cable complete with end fittings, (and preferably no coil, should such be available).

If you are DIY inclined, I suggest making your own cables with Toslink cable and Uxcell ends from eBay or Amazon.

References
1. DIY fiber optic writeup with parts. Chrisdarke, August 30, 2017. http://wetpixel.com/forums/index.php?showtopic=60564

2. https://wetpixel.com/forums/index.php?/topic/68006-group-buy-for-613-core-fiber-cable/
You can buy this fiber by the meter from this supplier:
https://i-fiberoptics.com/fiber-detail-asahi.php 

3. https://fiberfin.com/product/1-x-2-2mm-industrial-pof-cable-19-multi-core-ul-vw-1-rated-500-meter-spool/

4. Uxcell 20pcs 27mmx7mmx4mm Micro Strain Relief Cord Boot Protector
https://www.amazon.com/gp/product/B00XBG5U82/ref=oh_aui_detailpage_o03_s01?ie=UTF8&psc=1

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

= End =

9 hours ago, Kraken de Mabini said:

As Wetpixel members use fiber optic cables and end plugs (adapters) to trigger underwater strobes, I have gathered some practical information about these cables, plugs, and their problems.

Underwater Fiber Optic cables can are single or multi-fiber (strand), coiled or ‘straight’. 

Problem: Breakable Single Fiber Cables of 1 mm diameter, with a thin rubber coating are commonly sold. They are unreliable as the fiber breaks easily. It is important to watch out for, and not buy, them.   

Problem: Coiled cables, single or multi-strand, are a pain as the coil gets in the way, can get caught and lost while diving. As the coil stretches only a little, it is hardly useful. Coiled cables are best avoided.

Some solutions are: 

Make one's own Toslink Cables with Uxcell Plug Ends

A 2017 Wetpixel post by Chrisdarke and others describes how to make one's own fiber optic cables, using Toslink audio cable and Uxcell plugs (1). Both are inexpensive, tough, and readily available on the web, an excellent DIYchoice.

Toslink cable is 3 mm o.d. with a 1.3 mm single light carrying fiber.  Uxcell end plugs are glued to its end. The cable tip can be tapered with a razor blade, like sharpening a pencil, to fit tightly in the plug, then glued with rubber or ABS plumbers cement, and the tip cut with a razor to give a clean end. 
To keep the cable securely out of the way while diving, TimG suggests one weave it through the holes of the ULCS-style arms, where it is easy to remove, with no strain on either plug end (2).

Multistrand Cables.
Multistrand cables may be taking over the fiber optic cable world, as they are tougher and carry more light than single fiber cables. They have multiple fine fibers, from 9 up to 613 light conducting fibers per cable, and cost about $7.50 / meter. An example is the 613 core fiber cable, P/N MCQ-1500-22, made by Asahi Kasei in Japan. One advantage of a multistrand cable is it bends in the right angle of a Hotshot-style L-adaptor (2).
Otherwise, a cable with a high number of fibers is hardly a must for strobe use, as cables with a single, or a small number of strands, are also excellent choices to fire uw strobes (2), cost less and are easier to get.

Cable End Plugs
Most strobes and housings use the 7 mm diameter Sea&Sea type plugs (aka adapters or grommets) sold by Fun-In and DiverVision in Taiwan, and Amazon and uw photo stores elsewhere.
The plugs are made of one piece rubber or plastic, with holes for 1.5 mm cable, or are L-shaped, with two halves joined by screws, and a central L-shaped cable groove.  TimG tells us he uses a cable with Howshot L-adaptors at the housing end, and Inon double bush plugs at the Retra end. In his experience, the 613 and 217 core cables both work perfectly (2).

I have used the Uxcell strain relief plugs with Toslink cables for over 4 years to fire my Sea&Sea YS-D2J's and Inon Z240 strobes; these cables and plugs are tough, inexpensive, readily available and have worked perfectly for me, with no problems.

Complete Cables With Plugs
UW photo stores such as Backscatter, Reef Photo, B&H, Amazon and others, including eBay, sell complete cables for prices ranging from $18 to $135 and higher. As far as I can tell, if the buyer’s goal is to buy a reliable, low price, multifiber cable, the price has no relation to quality.
As it is important to avoid single fiber, breakable cables, one has to double check that the seller explicitly states the cable is multi-fiber. Buyer beware.

Suggestions
If you are not inclined to configure your own cable, my suggestion is to buy a low price multi-fiber cable complete with end fittings, (and preferably no coil, should such be available).

If you are DIY inclined, I suggest making your own cables with Toslink cable and Uxcell ends from eBay or Amazon.

References
1. DIY fiber optic writeup with parts. Chrisdarke, August 30, 2017. http://wetpixel.com/forums/index.php?showtopic=60564

2. https://wetpixel.com/forums/index.php?/topic/68006-group-buy-for-613-core-fiber-cable/
You can buy this fiber by the meter from this supplier:
https://i-fiberoptics.com/fiber-detail-asahi.php 

3. https://fiberfin.com/product/1-x-2-2mm-industrial-pof-cable-19-multi-core-ul-vw-1-rated-500-meter-spool/Diggy

4. Uxcell 20pcs 27mmx7mmx4mm Micro Strain Relief Cord Boot Protector
https://www.amazon.com/gp/product/B00XBG5U82/ref=oh_aui_detailpage_o03_s01?ie=UTF8&psc=1

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

= End =

Thanks for this great synopsis. 

Clears a lot of issues for underwater photographers. 

No 3 above url is:

https://fiberfin.com/product/1-x-2-2mm-industrial-pof-cable-19-multi-core-ul-vw-1-rated-500-meter-spool/

Diggy

Excellent post. I went to the DIY route last year based on postings in WP. It's great to be part of a group that so readily shares their knowledge and experience.

Thanks to all.

Harry

Amen, Harry

Yep, super run-up, Elias. Thanks!

That is a very nice summary, thank you

Question if I may - would there be any technical preference between 1 and 1.5mm ,613 core cables? (i.e. Asahi MCQ-1000 vs MCQ-1500 for example). That is other than bend radius. Both seem to have the same external diameter, ~2.2 mm, however different internal one.

Just curious, as trying to decide what to order.

As far as I can tell, to fire an underwater strobe, there is no technical advantage to either of these two Asahi cords.  I have used the commercial 1 mm coiled cable and it has fired my strobe reliably, as it should. My guess is the thicker cable should work just as well. If you are going to use L shaped plugs, then the thinner cord might be preferable.   

I use 3mm single core cables, with DIY Sea&Sea type plugs (TPU 3D print).
Unbreakable, good flexibility, very good light transmission even at low strobe power and only a few euros for several meters...

The only drawback I see is you cannot have L shape plugs, but this is not a problem on my setup

I just want to add that about 1 year ago I purchased these ready configured multicore optical cables, they are a bargain and as good as the expensive ones (some other poster whom I do not remember right now, here or on Scubaboard was sharing the link):

https://www.aliexpress.com/item/32966164929.html?spm=2114.12057483.detail.3.17d34826fOubSx

Before this purchase I was planning to make DIY, but at 25$/cable (including professional plugs), DIY does not look attractive any more...

Wolfgang

In general there is more light transmission with the 1.5 mm core fibers than with the 1 mm core. If you are using an LED to fire your strobes as opposed to an onboard flash and your strobes are hard to fire (S&S) then you might be in the situation where the 1 mm core is not as reliable as the 1.5 mm core. OF course if you use the Inon bushings you could put 2 fibers in each bushing. 

Bill

The Tooke cables are fine but at $30 with shipping a bit more expensive than making your own. Of course making your own has a fun quotient that should not be discounted.

Bill

As Bill says, making one's own cables is fun, plus one saves some pennies.  Toslink single core cable provides an easy way to make one's own, with Uxcell plugs. 

Coiled cable is to be avoided, the coil is unnecessary and tends to get caught, plus it fractures easily; it is a nuisance and waste of cable and money.

12 hours ago, bvanant said:

The Tooke cables are fine but at $30 with shipping a bit more expensive than making your own. Of course making your own has a fun quotient that should not be discounted.

Bill

Absolutely agree. It was so much fun. and then the satisfaction of the cables working. Its a huge "feel good factor".

Diggy

Just a note on the Tooke cables. I ordered one for an Inon strobe; this is one of the ones with the blue rings on the housing fitting. The fitting is metal and it was too large to fit in my Fantasea FA6400 housing hole. I used a dremel to make it fit but it was tight and the o-ring sat mostly above the housing hole.

In general there is more light transmission with the 1.5 mm core fibers than with the 1 mm core. If you are using an LED to fire your strobes as opposed to an onboard flash and your strobes are hard to fire (S&S) then you might be in the situation where the 1 mm core is not as reliable as the 1.5 mm core. OF course if you use the Inon bushings you could put 2 fibers in each bushing. 

Bill

One thing I found which was useful is that toslink connectors will fit in Sea&Sea receptacles, at least on my Nauticam EM-1 II housing.  They are square and just a light trim on the corners of the plastic plug allows them to plug in reasonably securely.

On 9/6/2021 at 7:44 PM, Kraken de Mabini said:

As far as I can tell, to fire an underwater strobe, there is no technical advantage to either of these two Asahi cords.  I have used the commercial 1 mm coiled cable and it has fired my strobe reliably, as it should. My guess is the thicker cable should work just as well. If you are going to use L shaped plugs, then the thinner cord might be preferable.   

On 9/8/2021 at 10:00 PM, bvanant said:

In general there is more light transmission with the 1.5 mm core fibers than with the 1 mm core. If you are using an LED to fire your strobes as opposed to an onboard flash and your strobes are hard to fire (S&S) then you might be in the situation where the 1 mm core is not as reliable as the 1.5 mm core. OF course if you use the Inon bushings you could put 2 fibers in each bushing. 

Bill

Thank you both. Yeah, that is exactly what i am wondering about. I am tempted to to get the 1mm cable, since this seems to have a tighter radius bend, as such should be more resistant to breakage. That said i am thinking about getting 10-20m anyways so might as well fashion 10 cables out of it and just swap if needed

I am using a Nauti LED trigger and Z-240s so I hope this combination will be fine with a 1mm...dilemma dilemma.

Certainly the 1mm cable and the Nauticam LED and Z240 works well at least in my hands

Bill

3 hours ago, bvanant said:

Certainly the 1mm cable and the Nauticam LED and Z240 works well at least in my hands

 

Yep, and for my Retras too

14 hours ago, bvanant said:

Certainly the 1mm cable and the Nauticam LED and Z240 works well at least in my hands

Bill

 

10 hours ago, TimG said:

Yep, and for my Retras too

Perfect, that is the answer i was looking for  Thank you!

Thanks for the tips with the TOSLINK cable. After breaking my second $95 Sea & Sea multistrand I sad screw it and gave TOSLINK a try. 

I 3d printed a jig for cutting the ends of the strain boots to be the length of the plugs on the standard multistrand, and to make sure the cut was orthoginal. Seems to work fine and easily triggers the YS-D2J on land. I will test them in water this weekend. I am using a LED trigger with my housing.