Digital SLRs and true TTL or E-TTL

Now that housings are out there for the D1 series and Canon and more likely with the proliferation fo D-SLRs just announced, I have a question about using TTL strobe use. (My Nikon D100 should be here in about two months)

The existing D-SLR offerings from Seacam and UK Germany don't or can't provide TTL function with existing underwater strobes.

Is this true of all strobes or just existing TTL strobes for film cameras? Will an Ikelite DS-125 provide true and accurate TTL if connected to one of these housings via a standard Nikonos TTL synch cord?

Some manufacturers have claimed TTL strobe control with digital strobes connected to housed prosumer cameras (e.g. Coolpix 5000, 995, etc.) Is this truly TTL control? If so, why won't it work with, say a Seacam D1X housing?

In order to provide true E-TTL function for the forthcoming D100, will it require a new TTL circuitry design of the synch cord to connect a digital strobe the hot shoe of the digital camera?

As you probably guessed. I would love accurate TTL with a housed D100 for some fine macro work. But will I get it?

See Steven Frink's take on D-TTL here:

http://www.stephenfrink.com/seacam/D1Xjour...urnal.shtml#VII

His solution? if you want TTL, you have to use the housed SB-28DX flash...

If you want manual flash w/ a Nikonos SB-104 or 105 - use a manual sync cord or "blind off" the TTL pin on the camera's hotshoe.

What does this mean? Hopefully Ike has some insight... I think he's played w/ this a bit also. How is the SB28-DX flash different than an SB-104? How is D-TTL different than "normal" TTL?

Cheers

James

It isn't looking good, from what I hear, to reverse engineer all the various "e-ttl" systems.

Which means the fuji S2 is the only one, of the current bunch, to provide ttl compatibility, underwater, when used with any current underwater strobes.

Don

Don,

Are you thinking about housing your Canon 1-D?? Does it have a popup flash or is it too "pro" for that...

I understand Nikon's D-TTL pretty well, but not E-TTL.

How many preflashes does E-TTL fire?

If it's only one, perhaps you could use one of Ike's TTL slave sensors - as long as you have a popup flash.

Cheers

James Wiseman

Hey James.

You know I shoot G2...

The D-TTL and E-TTL both prevent any current underwater strobes from working in TTL mode.

If there were a DSLR, with built in flash, you'd need a horribly big housing, to keep it dry, with the flash up.

I'm already really liking the small size, and low weight of shooting the G2, underwater. (As opposed to the N90s I was using previously.) The drawbacks of the P&S digicams are there, but I'm not currently convinced they are big enough to warrant putting up with the extra bulk, drag, adn travel weight, of a big DSLR, in an even bigger housing..

OK, maybe that's Sean that has the Canon 1-D. Sorry for the confusion.

Cheers

James

Canon's E-TTL has but one pre-flash so, in theory, Ike's slave strobes should work in TTL. No TTL through synch cord, though, unless you house the 550EX. From Ike's "hidden" D60 page:

"The strobe can be opened inside of the housing, allowing our DS Series digital strobes with wireless Sensor to provide TTL flash operation. A bulkhead is included to allow strobes with an Ikelite TTL sync cord to operate as a manual only flash. "

BTW, Ike is saving me lots of money by not building a D60 housing with a usable LCD screen. That's OK -- I'll use the money to go diving with my 4040z .

http://www.ikelite.com/web_pages/d60canon.html

FWIW, I think Ike is going to develop a new back for their MD series housing for the D60/D100/S2 which will allow ALL of those users to use all the buttons and view the LCD screen.

So start saving your pennies Mike.

Cheers

James Wiseman

I had forgotten about the Canon D60 page on our web site. How did MikeO know it existed? Situation confirms the complete void at helm of ikelite............

I must admit that it was James that first posted the site address. With a small assist from Google, I was able to find it again. I should also add that I wish all the companies I dealt with had "voids" that responded as quickly to questions! My penny jar is filling up as we speak -- just wish I could afford to put a few more nickels in . . .