Editor's Choice 2008: Video

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By Russell Hart

One of the problems with video, in our admittedly photographic opinion, is that it makes just about everything sharp in the scene you're shooting -- the indirect consequence of a camcorder's puny image sensor, which is often way smaller than a 35mm frame. The smaller image area requires shorter lens focal lengths to produce equivalent angles of view, and shorter focal lengths inherently produce increased depth of field -- more depth of field, meaning front-to-back sharpness, than you may actually want. And that in turn forces a sort of realism down videographers' throats. As photographers, especially coming from 35mm (or full-frame digital SLRs) and larger formats, we appreciate the isolating, often atmospheric effect of shallow depth of field. (Of course you can also achieve this when you're shooting 35mm movie film.)

But it turns out that you can "fake" shallow depth of field in video very nicely with a small-chip camcorder if you use Adorama's ingenious Pro Optic Depth of Field Adapter. Created by photographer and filmmaker Winston Vargas, the device mounts on the camcorder's lens, in front of which it places a Mamiya 645 lens. The Mamiya lens projects the subject's image onto a ground glass inside the Pro Optic, with the help of a supplementary lens (also inside the Pro Optic), the camcorder actually shoots the ground glass image rather than the subject itself. Most camcorder models have sufficient close-focusing capability to do this, but the Pro Optic incorporates a supplementary lens to ensure it.

Here's why this works. For a given angle of view, the image-forming lens (the Mamiya) is much longer than the camcorder's lens -- a normal lens for the 6x4.5cm format being 80mm as opposed to video's 6- or 7mm. (That's an estimate, cause we're not videographers.) The result: You get much shallower depth of field at a given aperture. You can even use the camcorder's controls to zoom into the ground glass for a tighter shot.

The Pro Optic actually keeps its ground glass vibrating whenever you're shooting. This prevents the latter's texture (needed for conventional manual focusing) from making the image appear "grainy." And you can use whatever Mamiya lens you want (Adorama sells them used), including telephotos that have even shallower depth of field. The drawback is that the lens must be focused manually. Focus puller!

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