I had a play with my 1DsII housing and Sea and Sea ttl converter yesterday and can confirm that second curtain sync does work. Set it up for a 2 sec exposure, and then watch for two distinct flashes.
I can also confirm that if you use a 580EX in a Subal housing with S6 connection and all six pins in your housing wired, you can get some really great features. But shooting in bright light (F14) the flash doesn't recycle fast enough for fast action shooting. It would be great for fast action shooting in low light though.
Cheers
James
A few posts back I reported that author David D. Busch (Canon EOS 40D guide to digital slr photography) stated that when 2nd curtain sync is selected :
"the flash will still fire as soon as the shutter opens, and then triggers a second flash at the end of the exposure.........."
Ryan however reported in a follow up post that this first flash was actually a preflash, occurring prior to the shutter opening.
I was able to contact David Busch and he agreed with Ryan. Mr. Busch went on to state that his sentence should have read:
"the flash will still fire as soon as the shutter release button is depressed fully (but before the shutter begins to open), so that exposure can be calculated. Then, a second flash is triggered at the end of the exposure..."
I spoken to Canon Australia again, and I have been told that the only option for 2nd curtain sync with the 40D (via the camera settings) is to have a 580EX MKII and bad luck if you want to use anything else .
That's correct. But FYI, you can get 2nd curtain with a 430EX flash but you have to select on the flash and not on the camera. Not that it solves anything for underwater...
Well, I can say this -- you do need to plan the picture then because on my four second exposure of my hand, there is a very annoying "preflash ghost" along side the "second curtain" properly exposed subject. That would be very annoying in a real photograph!
Would your hand have been visible even without a flash? If so, explains the ghosting even if the first flash precedes shutter opening.
Did anyone ever work out an answer to this? It's so frustrating! <_< Canon are letting us down here - rear-curtain would seem such a simple function to include.
I get rear curtain sync when I use the Sea and Sea eTTL converter.
Cheers
James
No, Canon have screwed us over.
I suspect it's a ruse to get 'dry' photographers to buy the newer Speedlites - a bit like Adobe forcing 40d owners to buy CS3 by not directly supporting its RAW format in CS2. Now where's that Nikon brochure...
