I Recant: The Worlde is Indeede Rounde

Hey Guys

I'm about as excited as a very excited person doing exciting things can be.

Having always argued that manual TTL with a DSLR is just fine, I took the plunge and bought a Heinrichs Weikamp converter to use with my Subal D30 housing and Inon strobes. And, lo, I have seen the light. Yippee! AWESOME. My pics are now almost all (95%) perfectly exposed. That snatched quick reaction photo? Yep, perfectly exposed now. I'm so happy with it I could squeak.

So far I have tested it out with a Nikkor 60mm and a 105mm. Perfecto. I need to set the EV on -2 but will transfer this setting on to the HW next time I uncouple it. I will have a go with WA at some stage but do not expect such good results.

So no more manual TTL for me. Thank You Mr Weikamp. The world is indeed round. And perfectly exposed. I recant all my former Luddite views.

you dive? with a camera?

damn, i should try that one of these days, i am an office junkie!

hows things across the way?

I would suggest you keep the EV setting on camera. Should you get a change in conditions to warrant different juice, you can't do it to the HW underwater.

My observations for Canon are that the use of the onboard flash EV comp is somewhat accurate. ETTL however exposes for white so it usually underexposes by 1-1.5 stops. Then you get a bright shiny fish and suddenly it's on again.

Mike: welcome back! Hope Canada was good. Its about time we saw you out on t'boat. Life on the Light side of Lembeh remains pretty peachy. We must catch up....

Drew: Many thanks. Maybe I'll hold off on that change. I don't want to spoil a good thing!

At a hotel in Bali (enroute to Lembeh tomorrow) I had my first chance to try the HW converter in combination with a pair of Hartenberger 250 strobes. The camera is a D700 in a new Seacam housing and the pool tests were the first time I've had it in the water. All pool test results were very encouraging. An over-under shot with the new 14-24mm at 14mm came out quite well and I was able to just hand hold the housing and shoot at f16 for the required depth-of-field by using ISO 1600. I'll try to attach a shot, but the internet connection is slow and it may not handle the task.

I got consistent flash exposures over about a 5 f-stop range working downward from full power flash and the under exposure warning signal. By about 5 f-stops, the exposures crept increasingly in the direction of increasing over exposure. This is the same thing that happens with regular TTL and film.

I tested the HW converter with both the 70-180 Micro-Nikkor and the 24-85mm lens. And at distances up to close to two meters. I also used both the flash compensation control and auto-bracketing applied to only flash output. And in both cases the results were consistent with what I have come to expect with my F5's and film. There is just a little more variation on the digital exposures than on film, which I think is due to the fact that the exposure is based on a pre-flash with the lens at maximum aperture and not during the actual exposure when the lens aperture is closed down.

I'll be at KBR tomorrow afternoon and will have a real chance to compare results on my D700 with Tim and his D300.

Fred

Fred

Is that 14-24 with the superdome? What extension length?

Drew,

The shot was taken with the 14-24mm f2.8 Nikon lens at 14mm. Exposure was with ambient light only at ISO 1600 at about 1/250th or 1/500th at f16. The camera was in my brand new Seacam D700 housing using the superdome with a 65mm extension ring between the housing and the superdome. I focused manually for the shot.

Fred