22 replies to this topic

[seadweller]

just curious which one works better and more reliably and what are the pros and cons of each. i have no idea so figured rather than flipping a coin id ask for some help from the experts. thanks a lot.

[Canuck]

Sorry, but I am confused by your question. TTL and fiber optic are not mutually exclusive. You can have TTL with fiber optic connections using several different strobes and/or converters. For example, you can optically trigger the Inon Z240 strobe using your camera's onboard flash, giving you TTL.

Were you asking about using electrical sync cords vs fiber optic cables?

[Panda]

Assuming you are asking about wire vs optical

Wire has to be sealed by o-rings and the socket passes through the housing so is a potential flood risk. Optical doesn't.

Optical requires camera flash operation to function. Wire doesn't.

Optical delicate. So is wire.

[seadweller]

Assuming you are asking about wire vs optical

Wire has to be sealed by o-rings and the socket passes through the housing so is a potential flood risk. Optical doesn't.

Optical requires camera flash operation to function. Wire doesn't.

Optical delicate. So is wire.

does requiring camera flash to function affect how ur pictures can be taken. ie slower shutter speeds...

[TheRealDrew]

does requiring camera flash to function affect how ur pictures can be taken. ie slower shutter speeds...

If you mean for using Fiber Optic, usually the internal flash is blocked so the flash from the camera flash does not really affect the shot. In other words either cable setup -wired or fibre optic - will not change how you use flash in a particular instance (subject to whatever general strobe adjustments are needed between the camera and flash - in other words if you are using fiber optics to TTL strobes and the internal flash is something you dial down, etc.). Having the internal flash having to fire could reduce battery time...

[Panda]

does requiring camera flash to function affect how ur pictures can be taken. ie slower shutter speeds...

It wouldn't change anything but -

with my old Coolpix 5000, using the camera flash would reduce the battery life to less than a decent dive
with my D80 in Ikelite, there is not enough room to pop the flash up enough for it to function

So you may have to choose the sync cord type to suit your particular camera setup

[Edward Lai]

When I use my Nexus D300 housing, I use the on-camera pop-up flash as the commander for controlling two housed Nikon flashes (I use two SB-R200 for macro and two SB-800 for wide angle). In both cases the signals are sent to the flashes by optical fibre. The Nikon CLS system works brilliantly even underwater! There is no worry of getting water leaked through the wire connections.

As the pop-up flash is only firing control signals, and doesn't contribute during exposure, I do not notice a significant drain of power from the battery.

I think optical connection is the future in u/w photography.

Just my 2 cents.

Edward

[DiveGirl 50]

My rig is a Canon 50D, Nexus housing, 2 x Inon Z240 strobes

I was previously using Fibreoptics, but have recently changed to Cable connections.

Main advantage of Fibroptics is the ability to use eTTL, and the fact that the fibreoptic system is waterproof.

Biggest disadvantage is that the internal camera flash has to fire with each photo taken. Problem here is that towards the end of a double dive, taking lots of photos, the camera battery is running down, causing a huge lag between photos while waiting for the camera battery to recharge. If you usually only do single dives you may not have this problem, but I was finding it a huge problem.

Also a handy hint if using fibreoptics - set the internal camera flash compensation to the lowest possible setting. It doesn't take much light to fire the strobes optically, and it does save battery power and heat buildup inside the housing.

I've also found that with my particular camera, the shutter speed is limited to 1/250 using the internal flash to trigger the fibreoptics. This may be different for other cameras?? No problem using cable connection, I can choose whatever shutter speed I like and the strobes will still fire.

I'm rapt in the cable setup now, having used both. I can shoot on continuous burst for as long as I like, limited only by the ability of the strobes to recharge.

Hope this helps.

DiveGirl 50
http://www.yambabeach.net.au

[jcclink]

My D300 battery will last 2 days (6-8 dives/600-700 shots) on a battery charge. Using on-board flash to fire strobes via fiber optics. In the camera menu I can set flash power very low, like 1/100 of full power. No complaints using fiber. Also a lot less maintenance, fewer o-rings to worry about. The LCD uses a lot of battery power, so minimize its use.

[Alex_Mustard]

TTL via fibre optic is a very neat solution that has many advantages over cables. Not using TTL (i.e. not firing the internal flash on TTL and thus the strobes) seems to be missing a major advantage of this setup. For me the biggest disadvantage of using fibre optics is that it limits your choice of strobes.

Although that would/will change when a non-Japanese fibre optic compatible strobe arrives. IMO Japanese strobes of the last few years (since YS350) have been chasing power in smaller and smaller units at the expense of quality of light. This is a non-issue for macro, but more significant for wide angle.

Alex

[craig]

IMO Japanese strobes of the last few years (since YS350) have been chasing power in smaller and smaller units at the expense of quality of light. This is a non-issue for macro, but more significant for wide angle.

I would have to ask, then, what have the non-Japanese strobe manufacturers been chasing? Why is a smaller package incompatible with quality of light?

[Alex_Mustard]

The packaging makes no difference to quality of light - but the flash tubes solutions in that packaging do.

The Japanese manufacturers seem to chasing ever more power (new strobes like the Z240 and YS110 are very powerful for their size) - at the expense of coverage, gradual fall off of light and colour temperature. Older Japanese strobes, like my YS120 were warmer at 5100K, for example, than these new strobes, but were bigger, took twice as many batteries and not much more powerful.

The US and European strobes seem to have a better quality of light in terms of softness, more gradual fall off, warmer colour temp - which comes from their circular flash tubes. Some might argue that the sacrifice reliability, though!

The downside for users is that there is no ideal all rounder! Small Japanese strobes on fibre optic TTL seems the best option for macro and larger, US or European strobes better for WA. And if you get both kinds you need both a fibre optic and electronic cables in you kit bag.

I guess I am waiting for Inon to make a wide angle strobe. Maybe 5 of their flash tubes arranged in a pentagon!

Alex

[Deep6]

I guess I am waiting for Inon to make a wide angle strobe. Maybe 5 of their flash tubes arranged in a pentagon!

Alex

Yeah, I'm waiting to see that one. I do favor the round tube light source. We can modify some of the sins of omissions with diffusers and white balancing and/or filters. Subjectively, there is something about the “feel” of the older strobes. May be it is the larger or slightly more parallel source of the light.


Bob

[craig]

The ideal flash tube is a point source. Unfortunately, a tube that small is limited in output. A circular tube is a good design because it more closely approximates a point source than a long, straight tube does. The reason a circular tube is better than a small, straight one like those in Japanese strobes is greater power handling. I've had small, straight video light bulbs that give 180 degrees of the smoothest light you will ever see. A circular tube is not inherently better than a straight one for quality of light IMO. It's hard to separate theory from practice.

From the little information I've gathered, hotter strobe tubes are more efficient and that's why the Japanese are running at 5500K. I believe that filtering down to 4500K breaks even on efficiency. As long as the strobe is easily filterable, I'm fine with 5500K.

I think it's a given that larger strobes have wider coverage, though how much really depends on the strobes you are comparing. Without diffusers, how much softer are they? With diffusers, how much different are they? The beam pattern is obviously the key differentiator yet it is hardest to quantify.

Yes, the Japanese value smallness in strobes like many other things. They are innovating there. They are also pushing fiber connections and optical TTL. I asked where the non-Japanese manufacturers are innovating because I'm not seeing much. Big, heavy packages with custom batteries and fat, circular tubes have been done for a long time now. Some are pursuing integral TTL but I want to get rid of sync cords.

Because of bouyancy, size and weight are really two sides of the same issue. The new Inon S-2000 is offering about 125 Ws/kg at over 650 cycles/charge and 1.5 second recycle time. How does that compare to other manufacturers? An Ike DS-200 looks to be about 105 Ws/kg, similar recycle times but with 4x the power and 1/4 the cycle count. Travel weight is potentially worse with custom batteries and chargers. An Inon Z-240 offers over 150 Ws/kg by my guestimate. Inon doesn't publish Ws figures but you can guess by cycle and battery ratings.

I feel that mounting and cabling are the big challenges to using multiple small strobes in place of a large one. I'd also like to see a mode of operation where slave strobes can be controlled by a manual master. Of course, like Alex I'd like to see Inon make a wide angle strobe at twice the power of the Z-240 yet stick with AAs.

[Alex_Mustard]

From the little information I've gathered, hotter strobe tubes are more efficient and that's why the Japanese are running at 5500K. I believe that filtering down to 4500K breaks even on efficiency. As long as the strobe is easily filterable, I'm fine with 5500K.

I think it's a given that larger strobes have wider coverage, though how much really depends on the strobes you are comparing. Without diffusers, how much softer are they? With diffusers, how much different are they? The beam pattern is obviously the key differentiator yet it is hardest to quantify.

Interesting info on the tube efficiency, Craig. And I too am a big fan of the Inons.

Just FY interest, this is the beam pattern that you get if you fire an Inon Z240 against a wall on land:

with apologies for the picture - this was part of my own soft box tests - not intended for publication! A cross shaped beam pattern, with such rapid fall off is hardly an ideal starting point. Although UW (in my pool versions of this photo) the diffusion through the water makes the cross much harder to see. Plus the INON diffusors do a very good job of turning this into a soft circle of light. My UW softboxes are better still!

Alex

[craig]

Also, keep in mind that the lens on the Inon is curved and will alter the beam pattern underwater. That's true of any strobe, of course.

I have a rig that I built to do underwater beam pattern tests but I fear it will soften the pattern a bit and wouldn't show that pattern as dramatically as your image, Alex. I agree that doesn't look like the ideal starting point. After seeing your result I looked at the Z-240 face and I see how that pattern comes about.

I have an S-2000 and the strobe tube diffuser is substantially different than the Z-240. I did a quick test similar to yours. First is the Z240:


Here's the S2000:

The Z240 appears to have a little better beam when diffused and is a stop brighter.

[Gudge]

My rig is a Canon 50D, Nexus housing, 2 x Inon Z240 strobes

I was previously using Fibreoptics, but have recently changed to Cable connections.

Main advantage of Fibroptics is the ability to use eTTL, and the fact that the fibreoptic system is waterproof.

Biggest disadvantage is that the internal camera flash has to fire with each photo taken. Problem here is that towards the end of a double dive, taking lots of photos, the camera battery is running down, causing a huge lag between photos while waiting for the camera battery to recharge. If you usually only do single dives you may not have this problem, but I was finding it a huge problem.

I'm using the same camera and strobes as you with fibre optics and easily get three dives out of the camera battery taking around 60 shots per dive. I have on a few occasions experienced a problem with waiting for the camera flash to recycle but figured out that this happened when I had under exposed the shot I had just taken by having the aperture too small or the strobe power to low. If the camera's metering system doesn't see enough light on the subject from the external strobes it will try and compensate by pushing the internal flash power as high as it will go resulting in a long recycle time. If the subject is well lit by the external strobe the camera's metering system will turn off the internal flash early resulting in a quick recycle time. If you're shooting a lot of under exposed shots the continual full dumps of the internal flash will also drain the camera's battery very quickly.

[bruceterrill]

Hi Guys,

I don't know if this thread has been hijacked or not, but from looking at Alex and Craig's results with their 'quick' tests,
I would say that it should be mandatory that diffusers not only be carried, but be fixed firmly in place! They seem to
make a mountain of difference.
IMHO.

Bruce

Edited by bruceterrill, 17 March 2009 - 11:48 PM.

[spachal]

Hallo, excuse my English please and welcome to my first post here :]

I'm newbie in the quetion of using external strobes under water, so I hope
that my questions will not be too foolish ..

I bought two Sea&Sea YS-90 TTL Duo strobes and I want to use them with my
Olympus C-5050 & PT-015 camera. In the first moment I thought that I'll use
them only like slave strobes, disable preflash on C-5050 and make exposals
only in manual mode (and in the future I'll buy better camera and use them
with electric cords and TTL function). But I found that it's possible to use
them on C-5050 like TTL strobes too. And, that this strobe supported cordless
TTL functon, which can maybe helps me a lot :]

I found that I can buy and use Heinrichs's Digital Adapter and connect it with strobes
via cable, using internal flash with TTL. But now, as I can see, it's maybe
possible to use only fiber optic cables with TTL too! Unfortunatelly I can't
use Heinrichs converter for Olympus-TTL, in PT-015 there is no hole for this.

So now please give me an advice what I should to do, here are some (maybe
totally pointless :] ..) options, but I want to use TTL in any case:

1. Connect both YS-90's slave sensors and outside case with fiber optic cables,
use internal flash in TTL mode for firing strobes (on strobe set up TTL and Slave on)

2. Connect only one external strobe's slave sensor with fiber optic cable, and fire
this one with cable by internal flash in TTL mode, and fire the second one
with cordless(wireless) TTL system (YS-90/30 TTL Duo should have this function)
- I suppose that if this will be functional, it shoul be the best solution

3. Connect both strobe's slave sensors and outide case with fiber optic cables,
use internal flash without preflash mode for firing strobes (on strobes set up
no TTL and Slave on) - I suppose it will works for sure, but without TTL, only
in manual exposal mode

4. Bought Heinrichs's digital adapter, connect it with first external strobe
via cable (Nikonos or S&S) and on second one use cordless TTL function, and fire
them with internal flash in TTL mode

5. Bought two Heinrichs's digital adapter, connect both external strobes via cables
and fire them with internal flash in TTL mode

6. Bough one Heinrichs's digital adapter and one DUAL sync cord for both strobes,
(it's probably the most expensive solution)

Of course, in all cases I will set up output of internal flash to minimum and
use it only for firing external strobes, the internal flash will not affect the shot.

Please, can you help me to choose preferably cheapest, but 'TTL workable" solution?
I want to use my camera with external strobe(s) for "wide shots" and macro too.

THANKS A LOT! :]

[ardy01]

What I dont understand is why someone doesnt make a slave trip that uses the inbuilt strobe light from a camera and creates the 2 wire trip necessary to fire a strobe in manual mode. I used to use one of these to slave a strobe 20 years ago. This would give all the old flashes around a new life (which might not please the manufacturers).

Essentially all you need is a flash of light and 1/2 1/4 settings for manual and its a great way to learn flash photography underwater.

I am still struggling to understand the full advantages of TTL over manual after using it for 5 years!