Friday, September 23, 2011

Fujifilm Finepix Real 3D W3 - Macro Stereo

If you look closely at the manual for the Fuji 3D W3 camera, it will tell you that that the focusing range is from 60 cm (2.0 ft.) to infinity. It will also tell you that the recommended range for taking 3D pictures is actually from 1.3 m (4.3 ft.) to infinity.

The Fuji 3D W3 has a 3D Macro mode that enables you to take pictures from 38 cm to 70 cm (1.2 ft. to 2.3 ft.) [wide angle] and from 1.1 m to 2.3 m (3.6 ft. to 7.5 ft.) [telephoto]. Doing macro stereo photography with a camera having a 75 mm lens separation (the Fuji 3D W3) is not a good idea. Why? It's because, unlike our eyes, the lenses do not converge toward the object to be photographed, and you end up with a left and right images that can not be fused by our eyes. But then, how do you do macro stereo (hypo stereo) with the Fuji 3D W3 camera? Well, you don't ... unless you have an optical device to reduce the lens separation (see Cyclopital3D) or a slide bar (more on this later) and a tripod.

You probably know that your Fuji 3D W3 camera has an Advanced 3D mode with one of the two options (Individual Shutter 3D) enabling you to take (with the left lens) the left shot and right shot (or the other way around) in succession, the stereo pair being saved as a MPO file. Now, if you also select Macro mode, you are gonna be able to take pictures of objects from 8 cm to 80 cm (0.3 ft. to 2.6 ft.) [wide angle] and from 60 cm to 3 m (2.0 ft. to 9.8 ft.) [telephoto]. What I am getting at is that if you use a slide bar to take the left and right photo in Advanced Individual Shutter 3D mode, you're gonna be able to do proper macro stereo photography.

The million dollar question is then: By how much should you slide the camera to take the right picture (after having taken the left one)? Well, all I can say with certainty is that Cyclopital3D uses a 25 mm lens separation in their macro close-up attachment. There's probably a magic formula that can give you the correct stereo base for any distance but I certainly don't have it.

Note that no matter what Fuji says, you should not take a picture of something that's too close. 10 to 12 inches is probably the closest you want to go, since it corresponds to the distance of distinct vision for most people.

Manfrotto makes some nice slide bars (used to be sold under the Bogen brand) but you could certainly make your own slide bar if you are of the DIY kind.

Of course, this slide bar business kinda defeats the purpose of having a stereo camera since all you need is a "mono" camera. On the plus side, having a slide bar also enables you to take intermediate frames between the left and right shots for proper lenticular imaging.

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