Friday, 21 January 2011

Pentax lens design patents related to M4/3?

In 2008, Pentax filed patents for some lens designs that have an image circle similar to that of the Four Thirds format. There has been some speculation as to what these lenses might be used for.

Some have speculated that Pentax might revive the 110 format, but for digital mirrorless interchangeable lens cameras. This format used negatives of the size 17x13mm (21.0mm diagonal), while the Four Thirds format has an active sensor area of 17.3x13.0mm (21.6mm diagonal). So they are virtually identical. Here is an illustration:


The lens designs Pentax patented were: 17mm f/2.8, 17mm f/2 and 14mm f/2.8. From a Micro Four Thirds perspective, these sound like sensible wide angle lenses.

Some have speculated that these designs were licensed to Panasonic and/or Olympus for use in their Micro Four Thirds lens lineup. To evaluate this, we can take a look at the latter: It has some resemblance to the Panasonic Lumix G 14mm f/2.5 pancake lens. We remember that when Panasonic first announced this lens, it had the specifications 14mm f/2.8. It was later changed to f/2.5.

Comparing the lens design layouts, we see the following:


Are these lens designs similar? I don't really have the right competence to answer this myself, but a simple inspection reveals that they are in fact quite similar. They have basically the same lens elements and groups. So it is not inconceivable that the Lumix G 14mm f/2.5 is based on the Pentax patent. But this is far from concluding evidence.

What about the Olympus M.Zuiko 17mm f/2.8 lens? Could it be based on the Pentax patent for a 17mm f/2.8 lens? Not really, is my guess. Their lens designs differ quite a bit.

1 comment:

  1. This is small lens. That's its main claim to fame, not the speed at f2.8, nor the focal length, the equivalent of about 35mm in 35mm photography. But on the small Olympus PEN body, this lens gives you a small package that takes quite good pictures without messing around with a zoom. In particular, it works well as a walking-around street camera, much like an old Leica or a Canon rangefinder of the 1950s/1960s. (See also the optical viewfinder which has image lines specifically for this 17mm lens.)

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