The reason I keep hoping that Sony will actually accomplish something with the Sony α brand is because it is derived from my beloved Minolta system, which I used for a decade from the 1970s to the early 1980s. During that time I owned a Minolta SRT-SC, XE-7, and XD-11, as well as a collection of Rokkor lenses (most MC, some MD) that included two absolute favorites, the 24mm MC VFC and 85mm 1:1.7 MC. I eventually sold everything except the XE-7 and Vivitar Series 1 90mm macro, which I still have.
When I transitioned from film to digital in the mid-2000s I had every intention of going back to Minolta, or Konica Minolta as it was known then. But by the time I was ready the rumors were already circulating that Konica Minolta was putting the camera division up for sale, so I waited and then bought into Olympus.
My support for Sony nee Konica Minolta is emotional and irrational, born out of rosy romantic memories decades old, rather than cold, hard facts.
While bumming through the internets I came across Luminous Landscape (another group of hopeless Sony α romantics) and an old article about the Leica M8. The Leica M-series camera is the granddaddy of mirrorless cameras. The article dealt a great deal with a key measure, the telecentricity coefficient, the ratio of the lens-to-flange-distance to the sensor (or film) diagonal. Quoting a bit from the article:
...it is possible to reduce to a minimum distance between the last element of the lens and the sensor or film. This characteristic is important because it allows you to avoid retrofocus designs in wide-angle lenses, and make them much smaller. Reflex [SLR] cameras have a typical distance between mount and film plane of 45 millimeters ... and this imposes the adoption of retrofocus designs for every wide-angle lens... These types of lenses typically have more lens elements and are bigger and more difficult to design for a good correction of aberrations... However, retrofocus designs have a particular advantage in the digital medium: the light rays fall over the film (or sensor) plane in a more perpendicular way. Electronic sensors have a thick cover of filters that deviate the incident light if it comes in acute angles. Reflex cameras have a key advantage here, because the distance between the mount and the sensor plane makes easier to get more perpendicular light rays coming to the sensor surface. The old advantage of rangefinder cameras in the film age is a disadvantage in the digital age, and the opposite happens for reflex cameras.In other words, it's good to have at least a 1:1 ratio or greater, which means increasing the lens-to-flange distance in relation to the sensor diagonal. This is one reason why Olympus originally designed the 4/3rds system with the largest ratio of all, 1.78:1.
That was back in the early 2000s. While Olympus was designing the 4/3rds system with a high ratio everybody else was adopting APS-C sensors to fit in their film-era 35mm cameras for essentially the same reasons; getting better edge-to-edge performance (less sensor area to cover) and hopefully a better system for designing less-expensive lenses, especially wide-angle.
Unfortunately Panasonic and Olympus discovered a bitter marketing truth, and that was the dominance of Canon and Nikon. As a consequence Panasonic pulled completely out of the 4/3rds DSLR market and Olympus eventually scaled back their efforts to just one body, the E-5. In the mean time they cut the flange-to-sensor distance in half, shrunk the mount, kept the same sensor dimensions and re-released the 4/3rds standard as the µ4/3rds standard.
Why? Marketing, obviously. They weren't going anywhere in DSLR sales. And technologically. Experience in sensor manufacturing combined with sensor technology advances and increasing faster embedded processors and sophisticated software allowed Panasonic and Olympus to minimize the telecentricity issues they first faced and move back towards a Leica-like "design". This gave them a truly smaller camera and matching lenses and thus a real marketing difference when compared to the Old Guard. Note that Leica's 35mm film telecentricity coefficient is 0.65. With all that in mind lets look at the telecentricity coefficient for three of the mirrorless systems that Matthew mentioned.
|Telecentricity Coefficient Table for a Selection of Mirrorless Cameras|
|Mount and format||Lens to flange|
Everybody is under 1, with the Sony E-Mount even lower than Leica. Keep in mind we're talking about so-called "cropped" sensor sizes, which are less than 135mm frames. I don't think it's an accident that Sony chose such a ratio for the E-Mount. I think there's a lot more going on with Sony sensors and processors that we're not fully aware of, something a lot more than just mere megapixels.
The eternal question is will Sony really succeed with the E-Mount-based cameras. Sony is going to have to make their lens lineup as strong as µ4/3rds, and as small in comparison to the body. I run in a two-year-cycle with regards to major camera purchases, and this year is the year I will probably pick up another body. This year is even more significant in that I may also switch to another brand. Whether I stay with µ4/3rds or switch to Sony remains to be seen. But Sony has definitely piqued my curiosity. Let's see what Sony can really deliver between now and the end of the year.