One flash in a stereo setup

Will the shadows be ok when using a flash from only one of the cameras?
Moderate stereo bases, 7 - 14 cm, and subject within 4 - 15 m, assumed.

Thanks.

DirkL wrote:

Will the shadows be ok when using a flash from only one of the cameras?
Moderate stereo bases, 7 - 14 cm, and subject within 4 - 15 m, assumed.

Thanks.

The flash for the Fuji Real 3D W3 is located between the two lenses. If the subject is close to a wall you see a dark shadow on the right side of the subject in one image and on the left side in the other image.  When viewing the image in 3D you can get a sort of shimmering effect with the shadows.  If you place the light above one of two cameras in a 3D rig you will get fewer strange effects but it would be best  to get the flash completely off the cameras.

The best way to use flash is to use it off-camera in a position that simulates more natural lighting, i.e. light from the sun. If you look at most portraits you will see the catchlight is from a light oriented above and about 45° to the side.

If you have a way of firing your off-camera flash with your 3D rig then these tutorials can help you learn how to use your flash. Whether your camera is 2D or 3D won't make any difference.

B&H - Bob Harrington - Off Camera Flash - YouTube

B&H - Bob Harrington - Using Small Flashes on Location Part 1

B&H - Bob Harrington - Using Small Flashes on Location Part 2

B&H - Syl Arena - Quick Start to Off-Camera Flash with Canon Speedlites

Wow, that was a comprehensive answer, thanks a lot

I intend to use a flash as fill flash outdoors. Yes, I noticed strange 3D shadows indoors with the W3 too, and I've read that using two camera flashes in 3D-macro might also result in problematic shadows. So I was wondering.

I am already using a remote control to trigger the cameras, maybe I am able to fire the flash too with it, have to look into it, but I don't think so. But I also will need a second tripod or such, which will be awkward. And since the is plenty of available light, maybe the shadows will not be so harsh?

DirkL wrote:

Wow, that was a comprehensive answer, thanks a lot

I intend to use a flash as fill flash outdoors. Yes, I noticed strange 3D shadows indoors with the W3 too, and I've read that using two camera flashes in 3D-macro might also result in problematic shadows. So I was wondering.

I am already using a remote control to trigger the cameras, maybe I am able to fire the flash too with it, have to look into it, but I don't think so.

No, if you use the same trigger for the cameras and the flash the flash will fire before the camera shutters open.  You need a second set of triggers.  With my 7D I use one set of RF triggers on one frequency to trigger the camera.  A second set of RF triggers operating on a different frequency are for the lights - one is mounted on the hot-shoe flash shoe, the other on one of my studio strobes.

But I also will need a second tripod or such, which will be awkward. And since the is plenty of available light, maybe the shadows will not be so harsh?

For my W3 I made a simple light reflector out of a piece of a plastic box, some aluminum foil, and a bit of glue and tape.  It has a tongue that fits between the camera body and the sliding lens cover to hold it in place over the flash.  The light from the built-in flash is directed upward where it bounces off the ceiling and then triggers my studio strobes.

Another way to use a built-in flash to trigger off-camera flash units is by using a fiber optic cable.  These are sold for underwater cameras but are expensive.  You can make your own for only a few dollars for non-underwater use.

ScubaBoard.com - my own DIY fiber optic trigger (for strobe)

PetaPixel - Trigger an External Flash with Some Fiber Optic Cable

If your flash doesn't have a built-in optical trigger then you could use the fiber optic cable with an optical hot-shoe flash trigger like this one.

B&H - Dot Line Hot Shoe Photographic Slave Flash Unit