DIY LED trigger flash

Using my DX-1G Sea&sea camera extensively last week in cold water, i noticed that (part from slow processing of RAW) I had to wait for the camera's flash to recycle while the YS110 recycled lightning fast.

Has anyone tried a small LED slave trigger in the hot shoe of the camera instead of the built in flash?

It would not require the camera to recycle the flash, and would not use camera's battery. If properly aligned, a very low power flash would be needed.

Comments? Anyone tried this? Anyone that knows the specification of the hotshoe connector?

Cheers

/O

I made the same suggestion to Ikelite so their DSLR housings could use fiber optic connections. I got not no response.

Using my DX-1G Sea&sea camera extensively last week in cold water, i noticed that (part from slow processing of RAW) I had to wait for the camera's flash to recycle while the YS110 recycled lightning fast.

 

Has anyone tried a small LED slave trigger in the hot shoe of the camera instead of the built in flash?

 

It would not require the camera to recycle the flash, and would not use camera's battery. If properly aligned, a very low power flash would be needed.

 

 

Comments? Anyone tried this? Anyone that knows the specification of the hotshoe connector?

 

 

Cheers

/O

Yes I have tried several. Some I have made myself. Zillion Housings uses a infrared flash trigger circuit inside their housings. Only trigger no TTL. Depending on which camera ie. Nikon or Canon TTL is complex. LED flash used in mobile phones uses a high capacity micro capacitor and is small enough to be fitted inside some housings. Some more experiment is needed. One has to be careful not to mix up the trigger pin to the signal pins otherwise one could fry the camera circuit. I have not had a satisfactory circuit that could do what I want - TTL. Pop up flash or built-in flash iwith fibre optic cable to optical slave strobe is still the most reliable for the time being.

Cheers

David

LED flash used in mobile phones uses a high capacity micro capacitor and is small enough to be fitted inside some housings. Some more experiment is needed. One has to be careful not to mix up the trigger pin to the signal pins otherwise one could fry the camera circuit. I have not had a satisfactory circuit that could do what I want - TTL.

Do you have a pin layout of the hotshoe? I tought the trigger pin's would be standardized , while the TTL sense may be different per make, correct? I'm happy with trigger so far, and make do with manual flash setting.

Do you have a pin layout of the hotshoe? I tought the trigger pin's would be standardized , while the TTL sense may be different per make, correct? I'm happy with trigger so far, and make do with manual flash setting.

I just stumbled upon that post, and this describes exactly what I wish I could do... Any progress regarding this, I am terribly interested !

I have a dx-2g housing, but due to a pb my pop-up flash is broken, therefore I can no longer use the optical cable to trigger my external strobe (ys-17), so I was thinking about finding a way to mount a miniature flash on the hot show, or build some sort of LED flash to trigger the strobe...

Any ideas ?

Alex

Sorry, no not on my end. David?

Such a LED trigger or better a micro strobe tube would realize the possibiliy to use optical triggered slave strobes on Ikelite DSLR housings. And exactly that may be the reason that Ikelite did not responded to diver daves1 suggestion to Ikelite.

Chris

Sorry, no not on my end. David?

Hello

I am still working on a eTTL or ITTL optical trigger. No luck yet. Nikon iTTL is more hopeful. The Zillion manual optical circuit is the only way at the moment. Not a good idea to trigger a flash tube inside a housing. LED flash is the way to go.

For hotshoe pin idagram just Google it. Here is a link to Nikon pin diagarm. Switch to Google images.

http://www.google.com/images?hl=en&q=n...sa=N&tab=wi

Cheers

David

Hello

 

I am still working on a eTTL or ITTL optical trigger. No luck yet. Nikon iTTL is more hopeful. The Zillion manual optical circuit is the only way at the moment. Not a good idea to trigger a flash tube inside a housing. LED flash is the way to go.

 

For hotshoe pin idagram just Google it. Here is a link to Nikon pin diagarm. Switch to Google images.

 

http://www.google.com/images?hl=en&q=n...sa=N&tab=wi

 

Cheers

 

David

So why is nobody/companies do this? TTL I mean. You get quicker recycle time and save battery on your camera, no need for TTL converter.

Dag

So why is nobody/companies do this? TTL I mean. You get quicker recycle time and save battery on your camera, no need for TTL converter.

 

 

Dag

Part of the problem is to do with the speed of the digital cameras coming out in the consumer market. Strobes with optical slave function has to play catch up. Inon is now sTTL type 4 which is the forth generation strobe. Works with most of the Canon, nikon and other brand of digicams. Believe me I am not the only one trying to hack it. Optical TTL I mean. One way around is to

get a small/cheap land flash, house it and trigger the optical slave strobes that way.

Cheers

David

.....One way around is to get a small/cheap land flash, house it and trigger the optical slave strobes that way.

 

Cheers

 

David

Hi David,

Can you clarify for me the above statement? I have Canon and will try to understand by this brand.

Are you saying that if I take a Canon strobe in a seperate housing it will have TTL capability via fiber optic connection? Or, are you saying to have a small cheap strobe inside on the camera and have this set up trigger underwater strobes (as Inons) via f.o. cable to get TTL?

I have been trying to figure out how to have TTL and multiple strobe ratio control from my 7D underwater via fiber optic. I have no clue what process is involved (strobe light or IR signal, or both?), but I use it topside and it works nicely in studio.

Any insight be much appreciated

Bo

I suppose the LED flash have evolved a bit since these:

http://www.khalus.com.ua/kh/data/component...luxeon/DS49.pdf

My hunch is that a LED flash has a slower response time and longer burn time than a discharge tube. Is that so, how does the timings compare?

In the data-sheet above seems to suggest that the shortest flash pulse is 50ms

If it is so that the timings are fundamentally different, it may be hard to mimic the timing and thus preserve the "TTL" functionality.

Comments please!

/O

Hi David,

 

Can you clarify for me the above statement? I have Canon and will try to understand by this brand.

 

Are you saying that if I take a Canon strobe in a seperate housing it will have TTL capability via fiber optic connection? Or, are you saying to have a small cheap strobe inside on the camera and have this set up trigger underwater strobes (as Inons) via f.o. cable to get TTL?

 

I have been trying to figure out how to have TTL and multiple strobe ratio control from my 7D underwater via fiber optic. I have no clue what process is involved (strobe light or IR signal, or both?), but I use it topside and it works nicely in studio.

 

Any insight be much appreciated

 

 

Bo

Hi Bo

Just let me clarify about the strobes first. Inon uses sTTL that is their jargon for System TTL and is proprietary system that mimics the flash of many brands of digicam. Canon's eTTL is very difficult to decode by electronic - ie. wire connection. I have only achieved using a manual non-ttl LED circuit inside a housing to manually trigger optical slave strobe. Non-ttl though.

Housing for Canon speedlites such as the EX 580 is available by various UW casing makers such as Subal and Seacam. These are expensive.

Some third party land flashes such as the Sunpak that uses Canon flash protocol (or similar)could work. Often the recycle time is slow but to trigger multiple strobes it has quite an interesting prospect. Unfortunately an external housing for the speedlite will have to use 6 pin cable like the S6. It is kind of defeats the purpose. I often uses a EX 380 speedlite in a custom housing on top of my Canon 5 D mark II for highspeed sync and as mutli-optical slave strobe trigger.

I have not tried putting one inside a housing. The most likely one to work is the EX 220 and it does not take up much room but there are no housing in the market that fits both camera and speedlite in the same case. It will have to be custom or DIY modified. I might make one and try for fun.

Come to think of it your 7D has a pop-up flash. Why not just use that to trigger all the strobes using fibre optic cables? Does you housing have one or more optical sync bulkhead?

regards

David

I suppose the LED flash have evolved a bit since these:

 

http://www.khalus.com.ua/kh/data/component...luxeon/DS49.pdf

 

My hunch is that a LED flash has a slower response time and longer burn time than a discharge tube. Is that so, how does the timings compare?

 

In the data-sheet above seems to suggest that the shortest flash pulse is 50ms

 

 

If it is so that the timings are fundamentally different, it may be hard to mimic the timing and thus preserve the "TTL" functionality.

 

 

Comments please!

 

 

Here is my two cents worth. The LED flash in mobile phones are slower and has not much power. At least with the ones I have been tinkering. The capacity for storing the pump charge is rather limited. It is almost a LED light. It is rather limited. The sensitivity of the phone's camera is boost up rather than the flash is providing most of the light.

 

In proper digicams, TTL means Through The Lens. The metering of the ambient light and adjusting the amount of flash to throw out is done through the camera's electronics and the discharge tube is powered by a powerful capacitor pump circuit. UW strobes have even bigger capacitors. An array of flash LEDs powered by lots of capacitors may work. Now all we need to do is work out how iTTL and eTTL really works.

 

 

 

Cheers

 

David

 

/O

Hi Bo

 

........Come to think of it your 7D has a pop-up flash. Why not just use that to trigger all the strobes using fibre optic cables? Does you housing have one or more optical sync bulkhead?

 

regards

 

David

Hi David,

Thanks for the explanation. I have not yet housed my 7D (but leaning to the Nauticam that has optical). Reports (like those from Backscatter) note slow recycle times when going optical.

But what I'm most interested in is using the 7D multiple-flash controller to use the "in-camera" flash-ratio control for macro, so the strobes will need to have the right canon TTL.

I need to know where the IR transmitter on the 7D is and where the sensor is on the Canon flash to connect them with an optical cable, and then DIY housing for the flash?

Bo

P.S. I agree with your signature.

More "economic" Housings for the Canon EX580 are available from: Fantasea, 10Bar, Aquatech, Patima.

The LED trigger would be perfect, but it seems to be too complicated to realize.

I would like to use a EX580 on my Patima G11 housing to see if it works better than any other system,

but as i have no EX580 the expenses for Strobe and Housing are quite "prohibitive".

Chris

More "economic" Housings for the Canon EX580 are available from: Fantasea, 10Bar, Aquatech, Patima.

The LED trigger would be perfect, but it seems to be too complicated to realize.

I would like to use a EX580 on my Patima G11 housing to see if it works better than any other system,

but as i have no EX580 the expenses for Strobe and Housing are quite "prohibitive".

 

 

Chris

Hi Chris,

In studio (topside) I'm using an old Canon 550EX, 420EX and a Sigma 500 Super (all 3 compatible as E-TTL slaves to my 7D controller). So, I'm forced to look at a DIY housing project for these. I just need to know where the IR and light flash impulses are generated and received for the proper placement of the thin optical fiber. I may have to look into multiple optical fiber connections to transmit the seperate light and IR, but I shouldn't have to since they are on different frequencies of the visual spectrum. Obviously, I know where the visible light is generated on the 7D flash and the general receiving area on the strobe, but would the beam of a narrow optical cable be enough to transmit all the necessary information?

It be really sweet if I could find a way. Perhaps I should just get a Nauticam optical cable first and try some dry experiments to see if anything (I want) works.

Bo

Quotes did not seem to work there so I cited below.

My point is (as when we started the thread) we would like too make compact flash with low power usage but very fast recyle time that sits in the hot shoe. The flash is too weak to illuminate any photo. It's sole purpose should be to trigger an external flash via optical fibre.

It would be nice to do this in LED technology, however my concern is whether it can be made as fast as a discharge tube. If we are going to trigger an external flash, say Inon with sTTL, the flash pulses from our flash must have accurate timings according to the camera's control so that the external strobe can mimic/ignore pre-flashes and shut down with the same timing as the internal flash.

Cheers

"Here is my two cents worth. The LED flash in mobile phones are slower and has not much power. At least with the ones I have been tinkering. The capacity for storing the pump charge is rather limited. It is almost a LED light. It is rather limited. The sensitivity of the phone's camera is boost up rather than the flash is providing most of the light.

In proper digicams, TTL means Through The Lens. The metering of the ambient light and adjusting the amount of flash to throw out is done through the camera's electronics and the discharge tube is powered by a powerful capacitor pump circuit. UW strobes have even bigger capacitors. An array of flash LEDs powered by lots of capacitors may work. Now all we need to do is work out how iTTL and eTTL really works."

Oskar,

sorry we got a bit off-topic.

Your idea of using a micros strobe is a nice one and would help some people (using Ikelite DSLR housings for example) to use optical slave strobes and may be useful for slow recycling times as well. Unfortunately we are talking of 1/60 or more of a second, so the LED must be very quick to light-up, otherwise thew would be always to late to trigger the strobe in the right moment. Once found a solution for that the comes another problem - or better limitation- as optical triggered strobes are sensing the (various) preflashe(s) to archieve a automatic exposure and this works perfectly but it's only possible with a strobe because of it's fast flash rate. Using the LED's may enable triggering tha strobe, but you would have to control exposure manually.

Here a article how S-TTL works: http://www.inon.jp/technical/sttl-auto.html or http://wetpixel.com/i.php/full/inon-d-2000...al-explanation/

Using the Luxeon Flash-LED the problem with the slow LED may be gone and it should work using it like a generic strobe to strigger the strobe, but there will be no i-ttl/e-ttl from the camera and you have to drive the external strobe in manual mode. Loosing the e-ttl/i-ttl mode may lead that the camera itself will have serious troubles in exposure control and has to be used in manual mode as well.

Chris

Yes it is true that the 7D has a built in flash and that is often the best way to use it, BUT the original poster was looking for a way to fire the flash manually not using the strobe at full power. If you use the built in strobe, even at 1/128 power it still will send out pulses to focus that will shoot off your external strobes. A small LED that fired even for 50 ms would allow you to get manual FO control of your strobes without waiting for the internal strobe to recycle or for the internal strobe to trigger the external strobes to send out a focus pulse

Bill