Dear all,

I have problems with my brand new UW Technics TTL converter with my rather old Subtronic pro 160 flashes in my new Isotta housing for my OM-1. With the correct setting (internal switch on TTL converter to position 8), most of the time the images are too dark, sometimes black. With setting for Inon Z330 (internal switch in position 6), it works much better, but everything else than perfect. Especially when there are white parts in the picture, the flash goes crazy. But sometimes also with very easy objects. The flash is connected via an Subtronic N5 cable, on the housing end (Isotta) 2 pins are inserted in order to maintain good contacts (there are 2 spring-loaded pins in the flash bulkhead). I have to say that this cables and flashes work perfectly fine since years with my (old) OM-D E-M1 and an TTL converter from Heinrichs-Weikamp.

Whenever the images are black or almost black, I realize a VERY strong preflash - or even only one flash. Thats difficult to say. Pavel from UW Technics was very cooperative, since at least one week I am in contact with him seeking for the problem. Pavel thinks that the problem is the connection, but I can almost rule that out, I already tried 6 different cables and new pins. I believe that my flash units (purchased in 2011) may be getting old and that the flash tube, thyristor, and/or capacitor are no longer powerful enough. Subtronic is already involved in my discussions, I already got another flash from them to testing purposes - which shows the same problem (also that one is about 10 years old, however).

Further considerations and observations:

• In general I can say that the preflash is much stronger than the preflash with my Heinrichs-Weikamp converter. It looks as if the pre-flash is already discharging the flash much too strongly.

• In manual mode, the TTL converter works perfectly fine as described in the manual (setting flash strength eigher via camera or on the flash; thats really nice!)

• my Hartenberger 250 hs flashes behave the same as the subtronics (except that in position 6 of the TTL converter I have to reduce flash strength by -1 to -2)

• Subtronic is currently working on a faster software for my flashes, but I think UW technics built the TTL converter for the original Subtronics without adapted software. Therefore, it should work (at least with new flashes also without software adaptation.

• Isotta claims that TTL should work without a converter, just with the originally shipped connector to the 2 N5 bulkheads.

• The old TTL converter works even with the new camera, but I don’t see a way how to install it into the housing without losing guarantee (soldering necessary) and furthermore, I would not have the option to switch between TTL and manual any more (in my old housing, there was an additional switch which disconnected one line of the TTL converter to the bulkheads to switch from TTL to manual during the dive)

My problem now is that I have no idea which parts to exchange: TTL Converter? Flashes (renew the internal electronics means about € 400 per flash)? No guarantee that it works after investing in renewing the electronics of the flashes or even getting new ones.

Any ideas are welcome,

Jens

You didn't say much about what you have the camera set at which can can make a difference. If you set the flash to second curtain sync on the camera you can use that together with a slow shutter speed around 1/2 sec or longer to tell if there is a pre flash as well as a main flash, that may help with trouble shooting.

I'm not sure I understand how you would need soldering to use the old TTL converter. The fact that the strobes work with the old trigger tells you something is not right with the new trigger. I see a few possibilities, with the m43 you don't tend to need as powerful a strobe as in wide angle shooting at f8 is generally sufficient.

You could buy new strobes ( huge selections these days,) pick ones that work well with the UWT trigger and OM-1

You could switch to fibre optic triggering with new strobes that will use that, plenty of strobes now work with R1C! olympus triggering, though ask here first there have been posts with some strobes proving troublesome. There have abeen a few posts on this recently.

You could trigger with the UWT trigger of you you could try using the mini flash for the OM-1 - that will work better in manual triggering than TTL possibly.

You could explore different cables as suggested by Pavel?

Thanks Chris for your help!

during my tests (above water) the camera was set to typical settings used under water:

F2.8-22, 1/60 to 1/250 s, flash at first curtain.

I tested with >1 second and second curtain flash in order to check if there is a second flash. --> Yes, there is definitley one (or two?) pre-flashes and a main flash. However, maybe with this setting the flash as enough time to recharge. So this does not prove that there is always more than 1 flash. My statment rather aimed at the question if there is ALWAYS only one pre-flash with Olympus or if, in some cases, there are also 2 pre-flashes. I read somewhere that in difficult situations (also when face detection is turned ON), there are 2 pre-flashes, in easier situations only one. No idea if this is true. Pavel knows for sure and I assume he is following this discussion. But it COULD be, that my problems just occur whenever there are 2 preflashes because they draw too much energy from the capacitor.

Regarding soldering:

In addition to the TTL converter there was a normal flash trigger delivered, consisting of a hot shoe connected to a small "mainborad", which is connected to the 2 bulkheads. To my understanding, I would have to exchange the hot shoe with the Hot shoe from my old TTL converter (which is not a mainboard, but a hotshoe by itself).

Pavel told me that the UW Technics trigger is not compatible with fiber optic connection to the Subtronic flashes. These flashes only work with electrical wired connections.

Currently, I am working with a mode for a weaker flash (setting 6 on the converter, intended for the Inon z330) and it somehow works, but not perfectly as it should. Changing to other flashes is tempting (especially with hss and/or RC options) but somehow risky since I cant be 100% sure where the problem is located.

I already tried 7 different cables meanwhile - all of them are N5-N5 wired, identical to the ones offered by Subtronic. All of them work perfectly well with other housings and flashes.

Regards,

Jens

I was thinking specifically of flash settings, I assume you are not using R1C1 as that requires specific protocol to intrepret the signals. Presumably you would need to ensure red eye reduction is off and check the various flash settings in the menu.

Regarding fibre optics I wasn't suggesting doing that with the subtronic strobes, just suggesting that many new strobes work quite well with TTL over fibre optics. I think the risk factor for new strobe sis quite small, many people are using both the mini flash and UWT riggers to trigger flash units both in manual and TTL. If you decide to go with new strobes juts put up another post asking about strobes that work well with the OM-1.

Thanks Chris!

to the best of my knowledge, all camera settings for the flashes are set according to the manual of the converter.

I will conduct several test dives here in cold Austria to see how the setup behaves. Real live testing is always better than dry training...

Cheers,

Jens