What is the upside of TTL with Digital?

[Ardy]

I am using some old Sea n Sea flashes on my new Olympus E-520 set up using fibre optics to slave fire the flashes.

I am new to digital UW and I am finding that manual works so well with the instant review and the histogram that apart from being able to shoot off a quick shot at something disappearing, I am not missing TTL. I always found I stuffed a few shots up with TTL anyway and it always struck me as a middle of the road compromise.

How many of you shoot in manual only and what is the BIG value in TTL with a digital camera?

 

[Cathy Church]

TTL simply improves your odds of a good exposure by reducing the chance of over exposure. While you are clearly good at judging your exposures and you can get along without TTL, there are many times when you are working in close and the distances are changing constantly, and TTL would be a great backup. You still want to use the optimum aperture for your scene, and you still need to take into account the sunlight exposure, but the TTL lets you just keep shooting as you get closer and closer to that turtle without having to risk losing the shot. TTL is a convenience, not a necessity. But generally anything that makes things easier underwater pays off in more "keepers."

 

[Ardy]

Thanks Cathy that makes sense. I did miss a shot of a yellow box fish whilst on my first dive with it and that was a pity so TTL would have made that.

I think as a starter it might be TTL for fish and manual for macro and WA. Then see where I go from there.

In other words it is really exactly the same as with film, it is just that manual is easier in digital.

 

[Cathy Church]

TTL probably works the BEST with macro, so keep using it there until you need to switch to manual. I use TTL as my default, and change when I need to. I am going on a shore dive now, so I can't stay longer to write. Poor me--have to go dive, oh, well...

 

[RonFrank]

This depends a bit on the camera one is using. Most Compact cameras these days have very little aperture range. If one is using a DSLR, then the aperture range is quite a bit larger, so TTL maybe more useful especially if one is changing the DOF often.

For macro work, TTL IMO is a godsend. In fact it works so well, I use it almost 100% of the time. For WA shots often the flash is doing a full discharge, so setting the flash at full is not a poor choice. On my Ike housing I can also adjust my flash exposure +/- 2 stops in TTL mode. This makes using TTL just so easy that there is no reason not to use it.

 

[Ardy]

Ron that is interesting. Being able to adjust your ttl would make it far more usable. I will certainly look for that feature in the flashes I buy. My big problem with it was that although you get the shot they all look like pictures from an automated film developer where everything is balanced out to norm.

I am trying to get my shots closer to what I want out of the camera and not just 'get' it and adjust it all in Pshop.

 

[Cathy Church]

Since Ardy is using a DSLR, I was answering only to that model. His housing has the variable TTL that adjusts the left and right strobe separately. You could also do that with the Inon strobes (when used with a compatible camera.) Otherwise, you can control the TTL output of the combined strobes with a strobe EV control found in most digital menus, even many compact digitals. Don't forget that when you are on program mode, the photo is already fully exposed with sunlight so that any additional strobe, TTL or manual, will only help to wash out the photo to a pale cyan.