Sensors: Size Matters

It's true: Size Matters.

Ok, I said it. Though I can also say it also obviously matters what you do with it.  

The digital photography revolution has seen a myriad of trends already in just a decade and a half, particularly in the compact market segment.  In the latter part of the aughts, there was a frivolous "Megapixel War" which saw typical camera specs balloon from 3MP to 12MP in just a few short years. While that has generally subsided, there remains an ongoing "Megazoom War" with bridge cameras capable of up to 50X Zoom levels.   Add in a host of other sexy features such as scene modes, sweep panorama shots, and Wi-Fi connectivity, and you have the making of a marketer's wet dream.

But when it all comes down to it, there is one factor more likely than any of the aggressively promoted items above that is likely to have the most impact on the image quality of the photos you shoot: sensor size.

For a number of years, this aspect of digital photography was all but overlooked as manufacturers focused their attention on scintillating specs such as Megapixels and Zoom range.  Even worse, to keep the costs of these seductive beasts at an attractive level, the consumer cameras of 2006-2009 typically had SMALLER sensors (1/1.8 on earlier models to 1/2.3 on later models) than their predecessors of just a few years prior.  They claimed the newer sensors were better as they did more to eliminate light noise.  Harrumph! 

If we think back to the film era, larger formats always allowed the potential for far more image detail.  While it was *possible* to take a better image with a 110 film SLR than with a cheap 35mm consumer camera, the same 110 camera could not complete with a 35mm camera of similar quality.  Meanwhile, the 35mm cameras covered only a fraction of the space covered by medium and large film formats! 

During the nadir of the High pixel count wars, there were a few compact camera models in particular, such as the Panasonic LX-3 and the Canon G-series line, that managed to keep some sanity in the compact camera mix by retaining 1/1.63 to 1/1.8 sensors. However, the price tags of these cameras combined with their limited zoom found them being overlooked by transit photographers who were wowed by the more affordable cameras with the more robust zoom lenses and smaller sensors. 

Digital SLR's: Not so standard

Interestingly, unlike their film based predecessors that pretty much took images of the same 24x36 size, digital SLR's are actually broken down into two flavors, full frame versions (that run on the pricey side) and "Crop" cameras that use an APS-C size sensor that is significantly larger than compact sensors, but still measurably smaller than the full frame cameras.  The result is that photos taken with these cameras have a multiplication factor involved that results in focal lengths of lenses that are longer than stated, so that a 50mm lens on an Crop camera behaves more like an 80mm.

Curious Aside:  The name "APS-C" is actually ironic.  In the mid-1990's, before the advent of the Digital era, camera and film manufacturers attempted to reinvent film photography by inventing a new format called APS (Advanced Photo System) that promised the ability to readily switch between Classic and Panoramic formats as well as easier film loading, and better information exchange between camera and film roll.  The system was only struggling to get off the ground by the time the digital era came along and delivered the final death knell.

To make things even more complicated, an interchangeable lens format called Micro 4/3s has been released with a 1 1/3" sensor, smaller than the APS-C but larger than nearly all compacts.  The advantages touted of cameras using these sensors is that they are much more compact in nature than SLR's but with better image quality than compacts.  As a result, cameras using this technology, such as the Olympus PEN EP-1 tend to have a niche market among camera enthusiasts and a hefty pricetag to go along with it.

Meanwhile, in the Compact Market  

Despite the attention to the Micro 4/3's product development, there remain new releases in the compact camera market that embody the legacy of cameras like the LX-3 by touting larger more capable sensors coupled with fast lenses:

• Sony RX-100 - a 1" sensor and a f/1.8 3.6x zoom lens.
• Fujifilm X20 - a 2/3" sensor and a f/2 4x zoom lens.
• Nikon Coolpix P780o - 1/1.7" sensor and a f/2 7x zoom lens.
• Canon Powershot G16 - 1/1.7" sensor and a f/1.8 5x zoom lens. 
• Panasonic Lumix LF1 - 1/1.7" sensor and a f/2 7x zoom lens.
• Olympus XZ-2 - 1/1.7" sensor and a f/1.4 4x zoom lens.
• Samsung EX2F - 1/1.7" sensor and a f/1.4 3.3x zoom lens.

There is variety to sensor types as well, but that may be for another article.  In any event, following this link to the visual diagram attached to this article may help make a little more sense to the widely disparate sizes in sensors among SLR and compact cameras.  It definitely helps to read reviews and compare features prior to purchasing a new camera to get the most bang for your buck.