Inon Z240 and Sea and Sea 110a under exposed ttl issues

[Ardy]

Hi Guys just got back from a great trip to Tulamben in Bali. Did 19 dives and made more of an effort with my photo's. Got some fine shots but all my TTL shots were under exposed slightly and although I upped the output on both the Inon and the SnS it made no difference to the results. I have to adjust the exposure on all shots and this puts another step in the post dive work that I would like to eliminate or more correctly reduce.

Any ideas?

Olympus E-520 in manual mode using optical cable attachments and Inon as main strobe and SnS as a (sort of) slave to fill flash.

 

[bvanant]

Both strobes were in TTL with fiber optic cabling?
Bill

 

[Ardy]

Both strobes were in TTL with fiber optic cabling?
Bill

Yes Bill

 

[bvanant]

See how they go in your kitchen. I believe that a yellow rubber ducky is the appropriate subject but a flower will work as well. Can you post a pic out of the camera that you think is underexposed?
thanks
Bill

 

[Ardy]

Will do Bill. The macro stuff is mainly fine it is the fish shots that I used to get well that have suffered on this trip. I did put the camera flash into + 0.7 to try to improve it but it made no difference. It must be something in the set up as it has worked pretty well before but never has been at a level where I do not need to adjust levels in post work.

This was taken less than 60cm (2ft) from them 1/100 sec F8. The viz was not great about 8m (24ft) this morning but at this distance shouldn't make too much difference.

 

[bvanant]

I will look at this in LR/PS and figure out what you should be getting with TTL based on the GN of the flashes. Were they pointing at each other by any chance? That turns out to sometimes be a big problem.
Bill

 

[Ardy]

I will look at this in LR/PS and figure out what you should be getting with TTL based on the GN of the flashes. Were they pointing at each other by any chance? That turns out to sometimes be a big problem.
Bill

Not sure Bill I was trying to do edge flash work with my macro stuff. It is something in the set up and I can't get my head around what I am doing wrong. Thanks very much for your help.

 

[bvanant]

Well if you are trying to get the black background with the strobes pointing inward, you will have to try them on manual mode. In TTL the TTL power setting flash can trigger the slave so that the slave doesn't fire at the correct time. In your kitchen try the strobes on both TTL and manual and if you have the optical cables try both with fiber optics. I don't have an olympus but I can easily get way underexposed pictures if the two strobes are on TTL and can see each other.
Bill

 

[Ardy]

Thanks Bill I think that must have been the problem. They seem ok when I do it in Manual. I started using TTL again only in 2010 and was happy with the results. I bought the Z240 last year this is only the second dive trip I have had it on. As I only do about 40 dives a year these days and most of that is during my 2 trips into asia I don't get enough time to practise with it. I find above water checking never seems to emulate what goes on under.

Thanks for all your efforts.