Strobe Sync Issue - Z330, fiber optic, Nimar trigger

Good evening.

I have an issue with my new photography gear. I'll explain it here written but I also made a video for those who prefer not to read.

The whole setup is new and the batteries are charged. I'm using a Canon RP in a Nimar housing. I have a flash trigger sitting in the hot shoe (battery is new as far as I know). I had to stick the LED to the optical bulkhead but I made sure that the LED sits right in the middle of it. The optical bulkhead was already installed by Nimar. It was delivered with a small adapter to put two cables at the same time. I am using new Inon fiber optic cables and 2 Inon Z330 strobes. 

Here is what I tested (and documented in the video):
When the shutter is actuated the LED Flash sync works every single time, a quick red light is emitted. (I confirmed with Nimar that the LED is indeed red and it's not a sign of low battery or similar).

When I hold the strobe about 10 cm close to the optical bulkhead this little LED is strong enough to trigger it. I did this to make sure that the camera & strobe are in the right mode to fire. Both strobes work with this test.

When I connect the fiber optic cables to the bulkhead and look at the ends, I can see the red light every time I click the shutter. 

I assume that with these steps I show that the camera, the flash sync, the cables and the strobes all reliably work. 

Now that I put everything together the strobes don't fire. My assumption is that the cables don't carry enough light to trigger the strobes? They seem clean and are original cables, so I assume good quality. Do I need to cut the tip off or something? I used them like I got them. They don't have any kinks or other visible issues.

Any recommendations on how to proceed? Do my tests clearly define the cables as the problem or did I miss something? 
Is there a way to adjust the sensitivity of the light sensor of the strobes?

Here is the link to the video: 

Thanks in advance for any help.
Patric

INON are normally known for having quite a sensitive flash trigger, so this seems unusual.  Only thought I have is perhaps neither cable is centered over the LED so maybe not enough light is getting through.  You could try rotating the plug in bulkhead and also holding it above the bulkhead to one side a little to try to center one cable end over the LED.  This would test the theory  that the offset cable in the plug is the issue but not provide a working solution.    Most other LED triggers I have seen use one LED per cable.

On the cables; it might be the cables but your test shows it would have to be both being a problem, which seems a little less likely.  I'm using an INON cable now to trigger my Z-240 with an onboard flash at 1/64 power and it works fine- but that produces more light.  You could also try removing the cable from your plug and holding it centered over the LED to see if that helps.  You could also try trimming the ends of the cables again with a sharp knife.  

Thank you Chris

I tried rotating the plug and the result is probably one flash out of 20 tries, not reproduceable and then only one of the strobes fires.

I also tried just holding a cable in place by hand, same result, not very reproducable and rarely in the right position to trigger the strobe. I'll have to check if I have a 1 cable connector today to try how that goes. 

Is trimming the cable safe? I guess I would use a razorblade or something similar that is new and sharp.

Since I bought the cables together, in case that there was a problem during production, they would most likely be from the same batch. I hope to try other cables in the next days.

 

Hi Patric,

This is well-known problem with  the Dual FO cable and LED triggering.

In optical bulkheads manufacturers usually use LED of narrow beam (8-15 degrees). Single LED optical bulkhead is purposed for a single separate FO cable.  In case of a Dual cable usage, LED fires mainly between optical cables.

How to solve the problem?

1 way:  

Use 613 type FO cable, it has the best transmission index on the market now, for example Dual FO cable HowShot 613L. Using it, test the triggering with concrete LED bulkhead. Usually this is enough solution, it works.  If transmission is still not good enough with Nimar LED bulkhead, then modify the dual connector on the cable (print plastic connector by 3-D printer, or other way) to place optical cores very close to each other inside the connector.

2 way: 

Install the second optical bulkhead on the housing. Use 2 separate (single construction) FO cables.

.

Hello Pavel

Thank you for your reply. 
Nimar sold me the complete package and also said that it has been tested with those strobes and dual cables (using the adapter) which worked fine. I could not find what type of cable (or how many strands) it is but I would assume that by purchasing the original INON cable I should be high quality?

I tried to hold one single cable (and also both close together) manually in the middle position and still could not trigger the strobes. 

For option 2, I don't see a place to install a second optical bulkhead on that housing, maybe I should have used a 5-pin system straight away.


 

Better try 613 fiber cable, at least for test. When you try such high transmission index cable, and positioned that single cable at the center of LED beam, and it does not work, Ok, then problem is that concrete LED trigger is weak / defected. Then, you can ask Nimar to change the trigger and optical bulkhead.

By the way, you also can install Optical TTL Converter kit including another optical bulkhead. It will work anyway, and you can have TTL with your Z330 strobes.

I was in touch with Nimar and it seems that Inon Italy shipped low quality cables. New ones are on the way to me. I found one single older cable and with that I can at least trigger one strobe.

Seems like Pavel was right with the quality of the cable...

Just posting an update.
I got the replacement cables today (It took a while because I live on an island, Nimar was very quick at sending them with DHL and they did not charge me anything for the replacements nor shipping).

Visually I could not tell a difference to the other cables but as soon as I plugged them in, both strobes fired every single time I triggered. I pulled a bit, twisted the adapter and rotated to various orientations, no matter what I did, consistent firing of both strobes. Against what I feared, their design of trigger and single optical bulkhead with double optical adapter works.

Pavel (here in the forum) was right about the quality of the cables and Nimar was also right about identifying the issue and sending me replacement ones. Can't wait to jump in the water with two firing strobes tomorrow. 

Fiber optic cables often don't fail outright, in my experience. I've had my share of issues yours as well, and it's frustrating that cables can appear to work, but won't trigger strobes underwater.

I find that the best way to test a cable in isolation is to hold one end to a continuous light source, and then look at the other end of the cable. If the cable is in good working condition, it will look like a solid circle of light. If it's broken, you'll still see light, but it'll have small black lines on it. 

I tried out the Nimar led trigger with several strobes (YS-03 and Meikon ST-100) and several fiber cables (Sea&Sea and HowShot).  It didn't work with any of the strobes and cable combinations.  However, it would trigger the strobe if brought into contact with the strobe sensor, without a cable.  Since then, I tried the above strobes, plus Z-330s, with the two cables and a UWTechnics trigger, which all worked fine with a single or dual cable attachment. Visually, the Nimar flash looks much weaker than from the UWTechnics.  I can only conclude that the Nimar optical signal is too weak.

I used the setup on several dives and snorkels now, macro where I don't extend the arm(s) much as well as wide angle with the strobes far out which sometimes pulls a bit on the cable. There was consistent firing, can't report any problems.