TTL not working

Canon 400D (XTi) - Ike Housing - Single DS125 - Ike cable.

In Bonaire for a few weeks and the TTL is not working. OK on the surface and for the first 30 ft, after which it seems to revert to full power. After this, I am also unable to change the flash exposure compensation. The orange TTL LED on the housing remains lit but the red LEDs will not light if I use the flash exposure compensation buttons. Never any dampness in the housing, Contacts look clean and bright.

Not a major crisis as manual is still working fine - just not so convenient for the type of snap-it photography that happens on a family vacation.

Suspect the cable but any response appreciated, including my potential stupid mistakes. Anyone know who in Bonaire might hold spares.

Thanks Tim

EDIT Further clue - Just noticed that the housing TTL light stays on when the strobe is switched to manual.

Canon 400D (XTi) - Ike Housing - Single DS125 - Ike cable.

 

In Bonaire for a few weeks and the TTL is not working. OK on the surface and for the first 30 ft, after which it seems to revert to full power. After this, I am also unable to change the flash exposure compensation. The orange TTL LED on the housing remains lit but the red LEDs will not light if I use the flash exposure compensation buttons. Never any dampness in the housing, Contacts look clean and bright.

 

Not a major crisis as manual is still working fine - just not so convenient for the type of snap-it photography that happens on a family vacation.

 

Suspect the cable but any response appreciated, including my potential stupid mistakes. Anyone know who in Bonaire might hold spares.

 

Thanks Tim

 

EDIT Further clue - Just noticed that the housing TTL light stays on when the strobe is switched to manual.

Given that is works OK for the first 30ft, then stops working, I'd think the cable was not the culprit. Is it possible that the increased sea pressure is depressing a button? You might also try cycling the power switch on the DS-125. Back when I used them, the switch could get a little "squishy" making it hard to know when you "clicked" into a seeting and not just in between; cycling it back and forth through the power settings sometimes helped. You might check with the Digital Photo Shop at Buddy Dive. John has decent gear selection there for rental but I don't know what they've got as far as Ikelite equipment.

Mike

EDIT Further clue - Just noticed that the housing TTL light stays on when the strobe is switched to manual.

That means nothing - the light will only change to 'Manual' when you press and hold both compensation buttons simultaneously for a few seconds. Physically setting the strobe dial to a manual power setting means the controller is not being used whatsoever. Adjustments to eTTL compensation are sometimes affected by the camera still performing exposure metering after a shutter half-press.

See the Ikelite eTTL explanation for a more thorough discussion.

You might stop by Fish-Eye Photo and talk to Tim. Extremely knowledgeable and friendly and helpful. His store is just off the roundabout, very close to ... everywhere!

Thanks for the replies. I'll pop in and see John and Fish Eye.

Yes Segal, I normally use the knob on the strobe for power control so thanks for the refresher link. I did ask for noob errors to be raised .

On my Ikelite housing there is a really tight fit between the hotshoe connector and the roofing of the housing. Thus, inserting the cemara in the housing fairly often pushes the hotshoe connector a small distance backwards, leading to erratic and highly unpredictable flash behaviour. This can of course be affected by pressure. I have no idea about the distance for the 40D set up,but if tight, this could explain a lot of weird flash behaviour, I have solved it by using a piece of eraser rubber cut to fit between the housing back and the connector.

Regards

Bent