Aquatica 300D will have TTL!

This is one example where the * button may come in handy. Frame Herb's smiling face in the center, fire the star button (*) to set the flash meter, then recompose and shoot.

That's the difference between "regular" TTL and digital types of TTL. The digital types set the flash power before the shutter opens, unlike film cameras...

Cheers

James

They have advanced flash modes like "3-D multi-sensor balanced fill flash" that is supposed to take into account for reflective subjects and small subjects that don't fill the frame. It just takes a bit of experience with the different cameras before you get comfortable with how the system works - but I firmly believe that it DOES work.

Actually, it doesn't always work, nor does it tell how it figures it out. If it doesn't work, and the user then adjusts it, it can then change it's calculation and negate your adjustment. Not that this matters much as no strobe does 3-D multi-sensor matrix yada, yada, yada.

I think some people are confused on how the camera and flash meters. Some have noted it correctly. These are two separate functions. The camera meters the ambient light exposure e.g. via spot, central or matrix (or evaluative if you prefer). The flash TTL works separately. Current Nikon TTL uses a five point system. So, although your camera may be in matrix metering mode, the flash TTL is looking at five points in the scene.

Just to add even more confusion, different models may handle compensation differently when dealing with exposure and flash compensation. My attention span is way too short to deal with it all. Hogan wrote a book. I haven't read it. We talked about it, but I can't even remember all the details. It was late. My brain was fried.

Preflash will not work with standard low technology strobes; the thyrister dischage is controled by an integral IC only found in surface dedicated units.

I love it when you talk dirty like that.

Wow, this thread really exploded in just a couple of days.

Regarding TTL, I have to say that with my D100/Aquatica housing, a housed SB80DX works extremely well in TTL for macro subjects and fish ID. I used manual exposure for years with the Nikonos V, but for close-up and macro, I did use TTL with the SB-105/SB-103 strobes and got pretty good results. The metering systems are so good with the current crop of DSLRs that TTL is no longer a joke, and I don't feel embarrassed to admit that I use TTL on most shots. I don't do a lot of wide angle, and I acknowledge that TTL is generally not as effective in wide angle.

Anyway, back to the original thread (which seems like a long time ago, but it only started yesterday). I hope someone does develop a DTTL underwater strobe for the D100. Until then, I love my housed SB80DX!

Jim

<!--QuoteBegin-jamesw+Jan 15 2004, 10:50 PM--></div><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (jamesw @ Jan 15 2004, 10:50 PM)</td></tr><tr><td id='QUOTE'><!--QuoteEBegin--> This is one example where the * button may come in handy.  Frame Herb's smiling face in the center, fire the star button (*) to set the flash meter, then recompose and shoot.

That's the difference between "regular" TTL and digital types of TTL.  The digital types set the flash power before the shutter opens, unlike film cameras...

:wink: Minolta 9000 circa 1985[/b]

Nice photograph, Bob.

My own experience with TTL goes back to the early 1970s when I had a Honeywell automatic flash, where the flash unit itself decided when enough light had reflected from the subject. It wasn't TTL, but it was a direct precursor to having a flash meter behind the camera lens. I don't know why Nikon (and others, I believe) decided to use a pre-flash TTL system, but I have to assume there are good reasons. In any case, the Nikon DTTL system appears to work well.

Frankly, I love technology if it allows me to spend more time with composition and creativity. I still have the option to use manual everything, but I usually prefer autofocus and exposure, with exposure compensation cranked in when I choose to.

But Jim where did you tie up that dinosaur prior to using that system.

Bob is trying to sell me a 14mm Nikon but I keep telling him I have Canon. Anyone else interested in one? The price is really reasonable

Hi all.

I have some experience now with eTTL underwater. As a Canon shooter who bravely/stupidly dives with his 10D in a EWA-Marine housing, I do at least have the advantage of using my 420EX in eTTL mode. (My setup got it's first real use underwater a couple of weeks ago during a week at Ningaloo Reef, and I've just been assessign the results in the past few days.)

Shooting with this combo, I found that eTTL worked well underwater, but flash and general exposure compensation were both very helpful/vital.

The best mode generally to shoot in was Av, which on Canon SLRs/DSLRs exposes the background for ambient light, and uses ETTL to correctly expose the foreground. You can thus adjust foreground/subject exposure with flash exposure compensation, and background exposure with general exposure compensation, to get the balance you desire.

Manual mode works bst for macro, as you can control and use large depth of field (shutter speed in Av would be too slow).

So the eTTL definetly works, but I'd always want the ability to tweak my exposure settings as above. It's vital above water. and I think even more so underwater.

If 300D+Aquatica had a mode of flash exposure compensation, it would be great. If there's no means of flash exposure compensation, eTTL functionality would be cripppled (in either Av or M, your shutter speed and aperture don't affect the foreground subject flash exposure - ie., you're completely relying on the automatic flash exposure which like all automatic exposure systems will sometimes be wrong).

Despite the above comments, I'm very excited about Aquatica's development. Good work, chaps!

I found more info on the Canon eTTL.

http://doug.kerr.home.att.net/pumpkin/300D_metering_DAK.pdf

It's too bad they don't include this in the manual. Based on this, I think eTTL would have worked on my blown out photo had I used the 7 point focus and let the camera select the focus point, which I think it would have done correctly. I or rather my cousin who took the picture following my instructions used center point focus, foucs locked on me and reframed the shot. Too much thinking.

Bob is trying to sell me a 14mm Nikon but I keep telling him I have Canon. Anyone else interested in one? The price is really reasonable

EXCUSE ME???

:angryfire: :angryfire: :angryfire: :angryfire: :angryfire: :angryfire: :angryfire: :angryfire: :angryfire: :angryfire: :angryfire:

How reasonable?

Actually flash exposure compensation is possible on digital rebel.

This program allows you to change it. The only problem is you can only change it by connecting it to the computer making it pretty much worthless underwater....for now.

So now I need to get a housing for my laptop?