Ideal Sensor Size ? Part 3, APS-C

Author  Andrew S    June 2013

Birdsville Hotel 2007.  I made this photo with a Canon EOS 20D which did a good job with it's 8 mpx sensor.

Background  In the early days of digital photography, imaging sensors were very expensive. So the first digital cameras with interchangeable lenses did not have full frame 24x36mm sensors.  The 3.1 megapixel Canon D30, introduced in May 2000 used a much smaller and less expensive sensor measuring 15.1x22.7mm.  This was close to although slightly smaller than the 16.7x25.1mm APS-C film size. APS stands for Advanced Photo System which was introduced in 1996, but failed to thrive because it delivered less image quality than standard 35mm film and in any event got rolled over by the march of digital image capture. Nikon's response was the 6 mpx D100, introduced in 2002, with a slightly larger sensor measuring 15.5x23.7mm. The megapixel race had begun.

Since then the great majority of interchangeable lens digital cameras have used either the Canon or Nikon (and others)  APS-C imager size. This has been a great  success for the APS-C digital format and, you might imagine, the basis for future triumph in the market place.

On it's own merits, APS-C could form the basis of a high quality photo system with enough image quality to satisfy the most critical professional and enthusiast photographers. The cameras are reasonably compact and the lenses can be smaller than those for full frame sensors.  Several makers (Sony, Fuji, Samsung, Pentax, Canon) of Mirrorless Interchangeable Lens  Cameras [MILC] have opted for this sensor size.

But my crystal ball becomes cloudy when I look at future scenarios for APS-C.

It seems to me that APS-C is under pressure from above (full frame) and below (Micro Four Thirds).

I think that CanoNikon want to upsell their customers to full frame. Both Canon and Nikon have a restricted lens lineup for their APS-C cameras. There are plenty of consumer style zooms but neither has the equivalent of the classic 70-200mm f2.8 tele zoom and both offer  a very restricted range of fast prime lenses for APS-C.  The message is clear enough. If you want the good gear, move up to full frame. 

We see a similar picture with the APS-C MILC's.  Sony offers a restricted lens choice for it's NEX cameras and Sony's promotional material clearly indicates they want you to step up to the larger format if you want the best gear. Fuji offers some interesting MILC's but again with a limited lens lineup and a rather niche approach to design. Canon may  have a coherent plan for it's mirrorless offerings but if so they are keeping it secret from potential buyers. Pentax tripped up with it's disastrous K-01 and Samsung may or may not be going somewhere with it's NX system.

On the other hand there is pressure on APS-C from below, in the form of the Micro Four Thirds format. The M43 sensor measures 13x17.3mm with a diagonal of 21.6mm which is just about exactly half that of full frame, giving a sensor area about one quarter of full frame.

Being mirrorless, M43 cameras can be, and in fact are, substantially smaller than those for APS-C DSLR's. But the biggest difference lies in lens sizes, which particularly at the long end of the spectrum are markedly smaller than those for APS-C cameras, be they DSLR or MILC. The latest M43 cameras have image quality very close to Nikon APS-C and in fact better than Canon APS-C.

I think that if a manufacturer gave whole hearted support to an APS-C system, either DSLR or MILC, it could be an ongoing success and serve the needs of enthusiast and professional photographers very well.  But none of them is giving the format full support.

Which makes me wonder...............