Fibre optics and TTL

Very Cool, thanks

 

Elmer

Hi Elmer,

Today i was informed that previous TTL prototype V2 is cancelled by Subal now. Subal is preparing another V2 board today.

I don't know anything about it's TTL accuracy or construction. This is absolutely another board. Sorry.

Hope it will be also nice. The future will show.

Pavel,

Thank you for the update. I have one on order, will have to wait and see what the Subal V2 will be.

Elmer

We have the the TRTL here and waiting to test.

One idiosyncrasy of TTL is that you cannot get full strobe power with it. Even though the pre flash output is small, it still stop the strobe providing a full power dump on the main flash.

All the best

Adam

I'll be really interested to read the TRTL test, Adam. Thanks for doing that.

That power limitation is a bummer. No way around it?

I'll be really interested to read the TRTL test, Adam. Thanks for doing that.

That power limitation is a bummer. No way around it?

Different strobes have different power discharge curves which really means they take different lengths of time to fully fire. Your onboard flash is fast and weak. Your external strobe is much more powerful but slower. So the fast weak flash tells your strobe to stop firing too soon.

For proper full power fumction you need a controller that speaks digitally to the camera and has been calibrated for your strobe.

Not if you are using the onboard camera flash as your control signal. See Pavels item #5 in post 10.

Different strobes have different power discharge curves which really means they take different lengths of time to fully fire. Your onboard flash is fast and weak. Your external strobe is much more powerful but slower. So the fast weak flash tells your strobe to stop firing too soon.

For proper full power fumction you need a controller that speaks digitally to the camera and has been calibrated for your strobe.

Many thanks. Yeah, that's what I understood from Pavel's really helpful explanation. It was just Adam's comment on the TRTL that made me raise the question. I thought the TRTL would overcome that problem.

We have the the TRTL here and waiting to test.

One idiosyncrasy of TTL is that you cannot get full strobe power with it.

I also did not test that board yet.

Thanks for the technical information.

..

Shurely you have nothing to do today, Adam? You could be testing that TRTL.....

Many thanks. Yeah, that's what I understood from Pavel's really helpful explanation. It was just Adam's comment on the TRTL that made me raise the question. I thought the TRTL would overcome that problem.

Trtl should not have the problem since it connects to the hotshoe.

Thanks. That's what I figured. Looking forward to Adam's review!

I see a Subal now have the V2 TTL system on sale on their website. Anyone have any experience of it yet? Elmer? Pavel?

Really helpful review of the Turtle on the latest UWP.

I see a Subal now have the V2 TTL system on sale on their website. Anyone have any experience of it yet? Elmer? Pavel?

Yes, i tested that V2 board (white color PCB). It has very nice TTL accuracy. And the 100% power of underwater strobe is available for TTL control by that board, another words it has full-size TTL (!).

Certainly, full-size TTL is available only for fully controllable strobes.

Tested strobes: YS-250, DS-161, YS-D1, YS-D2, Z-240. The board has a switch for those strobe types.

There are 2 pcs Optical TTL outputs and 2 pcs Wire TTL outputs onboard. Also, there is 1pc wire TTL connector for Nikon land strobe, because Subal also produces housings for SB-910/ SB-900.

New V2 board supports +/- TTL Flash Exposure Compensation (by camera wheel), TTL/M modes switching underwater, Manual flash power setting by camera wheel (in M mode). These features already became a good tradition for modern TTL products. The same features exist in Nauticam #26308 board, UWTechnics #11031 board and External #13038 converter, Aquatica TTL board, Hugyfot TTL board.

Thanks Pavel!

Sounds good.

Does anyone know if any manufacturer is working on a similar TTL device for Canon? More specifically, for the 5D Mk iv?

Check out the Turtle:

http://trt-electronics.com

Pavel, do you know if the V2 kit comes with the hot shoe to fit on the camera and connect to the V2 board - or is that an extra?

Pavel, do you know if the V2 kit comes with the hot shoe to fit on the camera and connect to the V2 board - or is that an extra?

Tim, sorry, i don't know.

But usually HotShoe connector exists in each Subal housing. User has to change only the board. No necessity to buy extra HotShoe.

Does anyone know if any manufacturer is working on a similar TTL device for Canon? More specifically, for the 5D Mk iv?

UWTechnics is also preparing Canon TTL for the market now. Product will be available soon.

Tim, sorry, i don't know.

But usually HotShoe connector exists in each Subal housing. User has to change only the board. No necessity to buy extra HotShoe.

Thanks Pavel

I've got a Subal ND800 with only the fibre optic ports - no wired ones. So there is no hot shoe connector. I suspect I'll have to buy one.....

I'll ask Subal and report back.