There's always a measure of satisfaction when you finally solve a puzzle, particularly when that puzzle is something you've lived with for a long time.
You experience a moment of "Eureka!" followed by a deep sigh of release, as years of pent-up frustration at not knowing the answer finally dissipate. Yesterday was such a day.
Fair warning: This is a somewhat dry technical discussion, so if you read on, you run the risk of being bored to tears. Don't say I didn't warn you.
Background
I use Zillion housings. I use fibre-optic cables to trigger Inon strobes, mainly my Z220 strobes, though I own Z240s and have recently acquired an S2000.
I really like this combination, because: Everything's light (Zillion housings are ABS plastic, Inon strobes are compact); The strobes run on universally available AA batteries; I use rechargeable NiMH batteries for maximum efficiency and minimal environmental impact; I'm in Japan a lot, so it's easy to get parts and servicing; Fibre-optic cables are a helluva lot lighter than sync cords, and they don't flood.
Most people who use fibre-optic cables use them with cameras that have built-in, pop-up strobes. Inon circuitry allows for the light from the internal strobe to control the external strobes, making it possible to use the native camera intelligence to control strobe output...hence terms like S-TTL and even wireless S-TTL...meaning you can just point and shoot without worrying about the strobes too much.
The problem is that I use cameras without pop-up strobes. Specifically, I've used the Canon 1D and 5D series, most recently the Canon 5D Mark II.
With no pop-up strobe, you need to get creative to use a fibre-optic connection, because fibre transmits optical signals (i.e., light), not electrical signals (which is what your camera sends out via the hotshoe).
The Work Around
So for several years, I've been using a work-around. Inside the Zillion housings I use is a clever proprietary mechanism that converts electrical input to optical output.
The result? I can fire my strobes via fibre-optics, even though I'm using cameras without built-in strobes.
The immediate drawback is that I can't shoot with any simulated TTL function, but that's not an issue for me, since I shoot everything under manual control.
The second, less obvious challenge, is that something funky happens in the electrical-to-optical conversion process, causing the strobes to misfire.
I discovered this with the first Zillion housing I used, with my Canon 1Ds Mark II. I got the housing two days before leaving for a month-long trip, and upon testing, discovered that every photo turned out black, or too dark relative to what it should be.
After a bit of screaming, running around in circles and calling people at random to plead for emergency assistance, a work-around materialised in the form of an extra part, called a Focus Light Controller (FLC), from Inon.
As I understand, this gadget was designed by Inon for use with Inon housings to stop activation of the focus light on their strobes, so it wasn't designed to deal with the issue I was facing at the time, and it's not even marketed by Inon (it's not on their website).
But, the FLC happens to cancel all pre-flash signals, so...on the (untested and unproven) theory that the problem I was facing was due to pre-flash signals, I invested (about US$450!) in a bunch of these FLCs and hoped for the best. I was desperate.
They arrived via courier the day before my departure. I tried them. They worked.
So I've made do with this work-around ever since. As far as I know, I'm the only person to use this unusual configuration. (If you're wondering what other people who use the same cameras, housings and strobes do...so am I. There's no way they're getting proper light output.)
Fast Forward
As the saying goes, "If it ain't broke, don't fix it."
Following this age-old wisdom, I continued using this work-around successfully with my Canon 5D cameras, and I assumed that the same solution would work with my new Canon 5D Mark II camera when I travelled to Izu recently.
Oops.
I didn't have time to test everything before departing, so it wasn't until I was on location that I discovered...nothing worked. At all. Excellent timing. *$@(%!(!#!!!
Anyway, with quite a bit of lost sleep and muttering under my breath, I managed to finagle around the problem and get decent photos, but it wasn't fun, and the circumstances were far from ideal.
So, once I got back to Tokyo, I set about trying to figure this out once and for all, with the help of Nagamatsu-san from Aquaforum and Kojima-san, the owner of Zillion.
The Resolution
I'll spare you the details of the many agonising tests, discussions and disagreements we had, but after a few weeks of back-and-forth, we finally figured it out yesterday.
In short, the conversion from electrical-to-optical requires a power source. Not a big power source, but just enough to kick the optical signal along. The design used in the Zillion housing draws power from the camera's battery. Since not a lot of power is required, it never affected the camera's performance.
What we discovered, however, is that the route through which the power was derived has an unexpected side-effect.
The Zillion conversion process takes power via the remote-release socket on the left side of the camera (when viewed from the rear). In the process of testing, we stumbled upon the fact that under certain instances, the camera outputs an electrical signal via that socket.
This unanticipated electrical output sent an unanticipated "fire!" signal to the external strobes via the fibre-optic cables, resulting in mis-firing/ mis-timing.
The FLC work-around I used worked because the FLC (mis)interpreted this "fire!" signal as a pre-flash and stopped it.
So we had an unintentional signal being stopped unintentionally, producing the desired result. Who says double negatives don't not work?
(Actually, there was an additional minor, unrelated issue that further complicated the situation, so in reality, we had an unintentional signal being stopped unintentionally before it was able to be stopped unintentionally, producing...a mess.)
In hindsight, this makes sense. But for the past several years, no one ever thought of this (at least, not that I'm aware of). We're not certain what the electrical signal is for, but I surmise that the electrical output is from the camera back to the remote release to let the remote release know whether the camera is focused or not.
Solution
So, now that we finally know the root of the problem, we have several possible solutions to test. Fortunately, for my upcoming trip to Tonga, I won't need strobes, so there's time to re-configure the conversion circuitry to fix the problem.
This situation doesn't affect a lot of people outside Japan, but if (a) you have a Zillion 5D or 5D Mark II housing, (b) you use fibre-optic cables instead of traditional sync cords and (c) you are using Z220 strobes, you will have a problem and need to contact me or Zillion.
For later series strobes, including the Z240, D2000, S2000 series, there may be an issue, but you can minimise the impact by ensuring that the magnet button on the right lower side of your strobe is in the "up" position in the case of the Z240, and that you do not have the magnets installed in the case of the 2000-series strobes.
Remember, this only applies if you're using fibre, and if you use a Canon DSLR that does not have a pop-up strobe, in a Zillion housing. (In other words, don't panic and flood me with emails.)
When we have out a permanent solution, I'll post again.
Aside
If you've attended any of my talks or been on trips with me, you know that one of the things I keep emphasising is that obsessing over the exact camera settings you use isn't a good idea.
This is a perfect example.
Had I been locked into a specific, tried-and-true, always-use set of camera settings, I would have never succeeded in getting the squid shots in Izu. As it was, I understood that there was insufficient light coming from my strobes, so I fiddled to get the appropriate ambient light exposure and minimised the requirement from my strobes.
In fact, I had no idea what the settings were until after I came up, downloaded the files and looked at the metadata in Aperture.
And finally...my heartfelt thanks to Nagamatsu-san and Kojima-san for spending the time and having the patience to slog through this time-consuming, tedious testing process!