Strange Behavior from DS-50 strobe

I'm having a problem with my Ikelite DS-50 strobe that makes no sense, and I'm hoping one of the wizards here might be able to explain it.

I'm using the DS-50 with the manual controller, which picks up the deflected light from internal flash on my Canon A-620 in Ikelite housing. What's supposed to happen is the controller picks up the light and sends a signal to the strobe, which then fires. The controller contols the amount of flash the strobe emits based on the setting I dial in. It works like TTL, and you're supposed to set the DS-50 to TTL rather than manual.

When I set it up this way and test it dry it works perfectly. Underwater, theTTL setting on the strobe does not work at all. To operate the system underwater, I have to set the strobe to manual and adjust the exposure entirely within the camera, set on manual. That might not seem so bad, but I have a smaller range of exposure options in the camera, and using the strobe on full manual means every flash is full power, which considerably reduces battery time.

I sent the strobe back to Ikelite. They said they were unable to reproduce the problem; in other words it seemed to work fine, according to them. But it doesn't. I will contact them again, of course, but I remain baffled about WHY a problem like this exists. There's no leakage, it's not a pressure issue. What else would cause a failure like this underwater when it works perfectly on the surface?

Any ideas?

Thanks in advance!

gc

Usually Ikelite will want your entire system so that they can pinpoint the problem, whther it be their item or the camera or the housing, and so forth. But your description suggests one of the areas that is affected by pressure...the sync cord is probably the problem.

Is there a switch inside the sensor? I can't remember if this sensor has one, but if so, set it to DS-50. All that I can think of is that the sensor got bashed around in shipping to you back from Ikelite.

Perhaps others will have some ideas here. I've only used the TTL version of this sensor.

Cheers

James

GC,

Here's the guide setting from Ikelite's site:

http://www.ikelite.com/web_pages/gide_cA80.html

Make sure your EV controller is set to NO PRE-FLASH and DS50 on the two small dip switches in the little compartment of the EV controller. Once I've set these I grease the metal threads and o-ring on the compartment plug of the EV controller. Then there is no need to take it part for a year or more.

As you state using the EV controller with your DS50 the strobe head needs to set to TTL as the EV controller is manually overriding the flash output.

Once final thing, make sure you have selected the flash icon lightining bolt and your Canon A620 flash is firing on every shot. Leave setting there and just adjust the EV controller flash output until you get a feel for what f-stop at what distance to subject gives you color and a pleasing exposure.

Hope this helps!

dhaas

"When I set it up this way and test it dry it works perfectly. Underwater, theTTL setting on the strobe does not work at all"

This statement is what leads me to believe it is the sync cord. If it works fine topside (Exposure, output, etc.) then it is most likely your cord.

Thanks for all the suggestions. To answer those who sent links to the Ikelite settings and instructions for setting the DIP switches, yes, I've followed all those to a tee. All settings are correct. Camera flash is firing properly. Ikelite did have my housing and complete strobe assembly when I sent it back to them.

The synch cord makes more sense to me, and I appreciate that suggestion. At the same time, it does work with the strobe on full manual, and I can take photos by adjusting the exposure values in the camera on full manual. But that reduces my exposure range, is harder to read and, as I said, burns up batteries faster. I want it to work as it's meant to. Anyway, if it's the cord, wouldn't that affect all functions when underwater??

Thanks again,

gc

Yep. One of the wires in the cord is the TTL wire. If it got damaged, then it can malfunction underwater.

Cheers

James

GC,

Sounds like someting in the cord is either severed or getting crushed at depth and the EV controller is not sending a fire signal to the DS50.

Any chance you have a friend with an EV controller and / or DS50 you could try and isloate either the strobe or controller?

Best test would at least be in a pool.....

dhaas

P.S. - When you set your Canon A620 to fire flash every time, is it reduced flash (???) output as all you need is a bit of flash to trip the EV controller....

Yes, I have used minimal flash as well as full flash. Same result.

I'll talk with Ikelite tomorrow about the cord theory.

Thanks to all.

gc

Hi all,

Thanks for the many replies and amazing interest in this topic. I got the strobe back yesterday from Ikelite, and it seems to be working. They repaired or replaced a defective 2K resistor in the strobe itself. I still have no idea why submersion would cause it to fail, but if it works now, I'm happy. I'll get to aim it at some fish this weekend.

Thanks again for all the suggestions.

Cheers,

gc