One of the under-appreciated advantages of the mirror-less, non-reflex (Micro) Four Thirds system is that, because the sensor surface lies closest to the lens mount of any interchangeable-lens camera, users can available themselves of virtually any (non Four Thirds) lens. All they have to do is obtain an adapter.

(Some refer to such cameras by the acronym "EVIL," for "Electronic Viewfinder Interchangeable Lens." I somehow doubt that Olympus and Panasonic are among them.)

Conversely, the non-system lens choices for DSLRs with sensors set comparatively far back from the mount (like Nikon) are concomitantly limited: focus at infinity is impossible without the aid of an extra lens element in the adaptor, which is guaranteed to adversely affect image quality.

Using an analogue and non-system lens foregoes such niceties as auto focus and auto aperture. You focus with the aperture wide open, before manually stopping down the lens (as desired). If the lens offers a maximum aperture of f1.8 and you stop down to f4, that's no big deal. Kit lenses rarely offer a wider maximum aperture. But stopping down to f8 or f11 will result in a rather dark viewfinder.

DSLR users with legacy analog lenses kicking around from the 35mm days, or who find tempting ‘glass' on ebay from time to time might want to peruse the catalogue of Fotodiox (www.fotodiox.com), a photo accessories specialist that provides a wide array of adaptors for virtually every mount.

At PMA 2010 in Anaheim, CA, the firm introduced a Micro Four Thirds adaptor line with shifting ability. Tilt and shift lenses correct for the geometric distortion that occurs when, for example, the photographer aims the camera up to shoot a skyscraper, or some other rectangular object. Unless he keeps the camera perpendicular to the ground (in which case, only a bottom portion of the skyscraper will likely be captured) the rectangular building assumes a trapezoidal shape.

Shift lenses can also be used to create panoramas that can easily be stitched together with software in post production. Curiously, Fotodiox refers to the latter and not the former in its description of the new adapters.

It should be noted that post-production software exists to correct the key-stoning distortion noted above (but at the expense of field of view) and to stitch images to create panoramas. Also, Sony is incorporating the latter feature into a wide variety of its compact digital camera line.

But purists after the finest image quality will likely find the optical tilt-and-shift route well worth investigating.

Article Tags:  camera, aperture, lenses, fotodiox, shift, focus, mount, system, thirds, skyscraper, distortion, note