Now you flash it, now you don't...

So, I was finally testing my used DS50 with EV Controller in a pool along with my Canon A520 (nothing special these days, I know) using the Ike 1-handle tray for the Canon housing. This is my 'practice upgrade' from using the A520 alone, prior to going as far as housing my Oly E330 and becoming task loaded with a dual-strobe setup, etc. Taking this down to the Flower Gardens this coming weekend (weather permitting) and wanted to verify all the seals and play around with settings, make sure I knew how it worked.

I'd already set the controller for the right settings (with pre-flash, DS50) and read how to adjust intensity. Also taped over the front (but not the sides) of the clear Canon housing with black electrical tape to block the forward internal flash, and made sure the camera was set to always flash. Verified above water that I was synced with a picture into a mirror, got my EV controller aim set and fixed, etc.

In aperture mode in my pool I played around with different apertures, different EV levels, even turned down the EC on the camera itself as much as I could. As it was a sunny day, even with the pool on the north side of the house and slightly shadowed many pics were still coming out pretty overexposed even at the minimum aperture, max negative EC on the camera, and minimum flash settings. (Shallowness of the pool is also no doubt a factor). I still couldn't get a 'water picture' looking up into the shadow of the house to go deeper blue at all with no flash.

So I figure I'd try manual setting on the camera. Only to find that the internal flash was firing, but the DS50 was not. I thought I'd misadjusted the angle of the sensor, and fiddled with that a while, before finally switching back to Aperture mode and getting the flash back. And then it hit me - reading the manual as verification after I dried off, sure enough I find that the A520 has a preflash in all the various assisted modes (Program, Aperture priority, Timing priority, etc.) but not in full Manual mode. DOING.

Since I really can't "open" the switch cover on the EV controller underwater to switch between the two, looks like I'll always be picking one or the other. Is this a 'common' thing among PnS cameras? Maybe I should also upgrade it?? LOL....

I suspect most, if not all P'n'S cameras will exhibit this behaviour.

The pre-flash is used by the camera to determine exposure settings. In manual mode, the camera doesn't need to determine exposure settings because it just shoots according to the values you set. Thus I doubt that any P'n'S cameras will fire a pre-flash in manual mode - it's redundant!

If the setting on the EV controller was available as a waterproof switch, then you would be able to change the strobe mode from pre-flash to no pre-flash underwater. At present, unfortunately, that's wish list material.

I'm not sure if other makes of strobe (that typically use a fibre-optic cable to sync with the camera) would provide the pre-flash / no pre-flash mode switch underwater, but if you want to switch between manual and Av (etc) modes alot, it might be worth a look.

take a look at the sea and sea rang of strobes as you can adjust flash or pre-flash settings on the strobe itself. Designed for P&S camera's.

take a look at the sea and sea rang of strobes as you can adjust flash or pre-flash settings on the strobe itself. Designed for P&S camera's.

I have the sealife SL960D. You can only change the preflash setting inside the strobe, so can't do it while underwater. It does have an amazing range of options though. You can set it for 0-4 preflahes, but can't change on the fly.

My olympus C4000 always fires a preflash even in manual mode. Actually I never use full manual. I let the camera do the focusing. I set the aperture and shutter speed. maybe if you tried that it would still fire the preflash.

The pre-flash is used by the camera to determine exposure settings. In manual mode, the camera doesn't need to determine exposure settings because it just shoots according to the values you set. Thus I doubt that any P'n'S cameras will fire a pre-flash in manual mode - it's redundant!

Heh, well when you put it that way, I kind of think "duh" at myself.

I'll just live with it for now, and know to leave it set to sync with a pre-flash if I'm going to shoot aperture mode and that I'll have to switch topside if I want to try full Manual.

Thanks also to Scubaspen - I did check out the S&S strobes and can see from the manuals it looks like you have the switching option underwater, but I'm already sunk into the DS50.

Hoping to get it wet for the first time (aside from pool practice) this weekend, weather permitting!