I’ve spoken to a lot of people who can’t wait to get their hands on the new Olympus EP-1 PEN camera. Yet almost all of them confess to not understanding the term “Micro Four Thirds”. So just what does it mean?
The first Four Thirds camera system pioneered by Olympus (and Kodak) got its name from the aspect ratio of the imaging chip the camera used. 4:3. As can be seen in the illustration below, the 4:3 image chip is close to the same height* as the more common APS-C imaging chip used by other manufacturers.
For illustration, not to scale
The shorter length of a 4:3 chip causes the chips proportions to conform to an 8X10 print. The APS-C chip’s shape conforms to an 8X12 print size. For all intents and purposes, a picture taken with camera based on an APS-C chip (Canon, Nikon, Sony) when cropped to 8X10 has a similar resolution as a like sized 4:3 camera (Olympus, Panasonic, Leica).
So how did “Micro” get introduced? By using an even smaller imaging chip? No, it came about by placing the standard 4:3 chip into a very compact camera.
Panasonic introduced the first Micro Four Thirds camera with the Lumix DMC G1. The G1 was and still is a revolutionary concept camera. By eliminating the mirror and prism of a standard DSLR the G1 could be made much, much smaller. Most of the size loss was in the camera’s thickness. Without the mirror box the camera could be half the thickness of a standard DSLR.
Because of the shortened distance from the lens mount to the image chip a new lens family had to be created. The Micro Four Thirds lenses are interchangeable between brands just like the original Four Thirds lenses. This means you can fit a Panasonic’s highly rated 14-140 zoom lens onto an Olympus EP-1 PEN camera.
The Four Thirds camera system was already smaller than the other competing systems. In order to further differentiate these new and even smaller 4:3 systems the name Micro was added.
Olympus has taken Micro Four Thirds technology one step further. By eliminating the eye level viewfinder and the right side finger grip, the EP-1 camera is the smallest yet. (No, it won’t fit into a shirt pocket… maybe into a large cargo pocket on your shorts though)
This means that the Panasonic G1 and the Olympus EP-1 will likely appeal to very different users. Without an eye level viewfinder the EP-1 will be much more difficult to use outdoors on a sunny day. A soccer parent or vacation photographer could well be frustrated by the lack of a viewfinder.
OK, to sum up. The Micro Four Thirds camera systems from both Panasonic and Olympus don’t use smaller imaging chips. They have smaller camera bodies to earn the name “Micro”.
The new system departed in many ways from standard DSLR construction in order to achieve its small size. However, since the system retained the large, high resolution imaging chip the original system was known for, image quality didn’t get reduced with the camera’s dimensions!
*7/19 – After re-reading the post I corrected my description on the comparative sizes 4:3 to APS-C imaging chips. The 4:3 chip is just under 2mm shorter on the short axis than an APS-C chip. Previously I had described them as “virtually the same height”.