SLR: Setting Standards?

A mighty lump of a camera: The new Olympus digital SLR might look like this mock-up-or it might not, says Olympus.

Ever since the mid-1930s, when Exakta decided to go it alone with its own bayonet lensmount, we have suffered the proliferation of many noncompatible 35mm camera lensmount systems. Nikon, Canon, Minolta, Leica, Olympus, Mamiya, Contax, Miranda, and Petri are only a few of past and present SLR makers who have made it impossible for consumers to join lens A with body B. There may be some truth in the accusation by photographers that this Tower of Babel in lensmounts has been encouraged by each company's bean counters to make certain that once you decide on a camera and lens system, you are darn well going to have to stick with it. But many camera and lens designers insist that they have evolved their respective lensmounts to be more capable and convenient than those on other brands.

Digital SLRs with interchangeable lenses have compounded the problem. Because so many digital SLRs use smaller-than-24x36mm sensors, you must, in effect, multiply the marked focal length of the lens by a specific value to calculate the 35mm-equivalent focal length. For instance, a 28-105mm zoom becomes a 39.2-147mm zoom if the multiplier is 1.4, or 47.6-178.5mm if the multiplier is 1.7-all because we are basing digital SLRs on 35mm camera bodies and lenses which actually cover greater areas than needed for cameras with smaller sensors.

Because of this multiplication factor, ultra-wide-angle lenses are only available on digital SLR cameras using big (and expensive) full-sized 24x36mm sensors. With a sensor requiring a 1.5 multiplication factor, you need a super-big and expensive 14mm lens to reach the 35mm equivalent of 21mm.

Olympus is proposing we ditch the whole business and initiate an entirely new digital SLR system. Based on a 4/3-inch (diagonal) sensor size, and lenses covering just that size sensor, digital cameras would be smaller and lighter. But Olympus is going far further by proposing that the 4/3-size sensor be made a standard for future digital SLRs built by other companies, along with a common lensmount, back focus, and the same lens-to-camera-body electronic interface. Thus lenses and cameras made by all manufacturers would be readily interchangeable and all lens' focal lengths would be as marked.

Further, Olympus is suggesting an industry-wide Universal Digital Interchangeable Lens System Forum to promote the acceptance of the "4/3 Standard" by other camera manufacturers. Olympus announced that Kodak has already climbed on board as a partner by agreeing to implement the system, and that Fuji has also agreed to participate.

Olympus points out a distinct optical advantage that the smaller-diameter lens system and smaller-diameter sensors would have optically over the larger-diameter 35mm lens system. Olympus explained that light rays striking a digital image sensor at angles of much less than 90 degrees may not be captured by CCDs with sensors having tiny micro lenses at the front, thus causing poor imaging performance. This particularly affects image corners when using wide angle at wide apertures. Other camera and lensmakers, however, say that this effect is less when 35mm system lenses are used with smaller-than-35mm sensors, and that some of the new full-frame 24x36mm sensors, notably the CMOS type, can virtually eliminate the problem.