Micro Four Thirds is not so much a new format in digital photography (“standard” Four Thirds using the same sized sensor has been around for a number of years) as a new concept, and one which is taking the world of photography by storm. So much, in fact, that it has already spawned a number of imitations from Ricoh, Samsung and Sony – using different sized sensors but all broadly based on the same concept, and others are bound to follow. For now, though, :43: remains the undisputed leading format in this class of camera. But what next for the genre, where do we go from here? For the answer, I believe we have to go back to the future. Let me explain. Prior to 1925 medium format roll film reigned supreme, despite plate cameras still offering significantly better quality, due to greater portability and ease of use. You could use a digital analogy of APS-C sensors and “full frame.” In 1925 that all changed with the introduction of the Leica, a design that Oskar Barnack had been working on for about twelve years and which utilized the much smaller 35mm film format originally designed for movie cameras. Despite the obvious trade off in quality the new miniature format was a resounding success and the rest, as they say, is history. This new film format could be compared to :43:. But how did 35mm cameras develop and how is that relevant to :43: when surely the only thing they have in common is a smaller than traditional image forming area? Already, in fact, there are startling parallels. Initially, the new breed of 35mm cameras were quite expensive compared to the established roll film models, in much the same way as :43: cameras are currently more expensive than entry level DSLRs, and formed a bit of a niche market for serious and well-heeled photographers. As time progressed, however, and other manufacturers supported the format, prices dropped in relative terms and 35mm cameras enjoyed mass appeal, as no doubt :43: is destined to do. It's interesting to look at the designs of the early 35mm cameras in relation to the early :43: offerings. It's O.K. making a tiny body just big enough to house the film, or sensor, but some provision has to be made for viewing the subject. Initially 35mm cameras had either a very small and inadequate built-in finder or a much better external finder that clipped in the accessory shoe, making the camera more bulky. I suppose the modern parallel in :43: is the choice between LCD screen only, which has disadvantages in certain situations, or a clip-on EVF. 35mm cameras continued to evolve with bigger built in finders, at the expense of larger body dimensions, a bit like the Panasonic G1, except of course that this pre-dated the other :43: cameras that provide an LCD screen only. However, by refinement of design and improving technology, the nirvana of truly pocketable 35mm viewfinder/rangefinder cameras was eventually achieved culminating, it could be argued, in the Olympus XA. During the same period, of course, film quality improved in tandem with camera development. Initially convenience was the only attraction of the smaller film format, which suffered in overall quality in much the same way as :43: does to some extent compared to full frame. But eventually emulsion technology improved to the stage that for a while, before the introduction of Velvia, it could be argued that 35mm Kodachrome 25 surpassed the E6 120 roll films available at the time. Whilst this is unlikely in digital sensor terms, it's not inconceivable that the technology will progress to the point that for all practical purposes an :43: sensor will equal anything bigger. To my mind it's no coincidence that Olympus, makers of the superbly performing yet diminutive XA and before that the still highly regarded 35RC should also be in the vanguard of designing and developing the new breed of :43: digital cameras. Olympus have chosen to style their initial models for this format on the PEN range of 50 years ago, no doubt partly for nostalgic reasons, but I think if we look back to the XA we get a glimpse of how the future may look for :43:.