Camera Sensor Evolution

2006.09.09

There seems to be two things driving improvements in camera sensors, technology and marketing. Technology is improving the process by which sensors are made. Marketing is concerned with selling what technology produces. Both of these drives together do not always push evolution in the ideal direction.

Marketing is concerned by things which are easily measurable. Take the recently reviewed Panasonic Lumix FZ50, 10 Megapixels is more than its predecessor's 8 megapixels, those numbers are easy to understand. Less noise than before is an improvement, but it is hard to measure. It can also be the result of some untold compromises. As DP Review's review shows on page 7, noise levels are not so high with the FZ50, but details are relatively low. DP Review says:

Noise is visibly lower, but you're sacrificing even more detail, producing results that - though very clean and smooth - are actually softer looking and less detailed, despite the extra two million pixels.

All in all, the FZ50 seems like a good camera, but its marketing-driven evolution has sacrificed image details. Imagine how good it would be with its lens, full manual controls and speed of operation but with a Fuji SuperCCD instead or at least a good 6 or 7 megapixel sensor.

Fuji is trying something different lately, it is pushing high-sensitivity performance and marketing its cameras as having ISO settings up to 3200, see the Fuji Finepix F30, for example. This is also something measurable. After all, ISO 1600 is more than ISO 400. At first glance it is simple to understand. The problem they are facing now is that not all ISO settings are created equal. Fuji actually does very well at high-ISO since its 4th generation SuperCCD. Several other camera manufacturers have added high-ISO modes to their cameras, Olympus even claims ISO 4000 on one particular model. Even Panasonic introduced ISO sensitivities up to 1600 with its Lumix FZ7. No one who saw those pictures was impressed, they were devoid of detail and extremely soft looking. However, since ISO 1600 exists on the FZ7, it could be marketed as such. Megapixels however are harder to fake. In some countries, there are even standards on how megapixels can be counted.

Thinking about high-ISO vs megapixels, high-ISO allows more photo opportunities, more megapixels allow bigger print sizes. Both are useful, but since the average consumer makes rather small prints and takes lots of indoor photos at social gatherings, high-ISO sensitivities are generally more useful.

A few years back, Fuji tackled another shortcoming of digital image sensors, their limited dynamic range. For reference, dynamic range is the span from the lowest light levels to the highest light levels a camera can capture in a single exposure. With its SuperCCD SR, Fuji produced 3 cameras which were capable of capturing more dynamic range than any other digital camera. The first one was the Fuji Finepix F700, pictured here, image curtesy of Fuji. The most popular one turned out to be their high-end DSLR, the Fuji Finepix S3 Pro. Although the S3 was quite slow compared to other DSLR cameras, it quickly became a favorite of wedding photographers which have to cope with bright white wedding dresses and black tuxedos.

Dynamic range is an important area for improvement because the human eye is much more sensitive to light levels than it is to color. So much so, that in television broadcasts, color is often sent at half or one quarter of the precision of luminance information. Our mind also remembers details in both dark and bright areas even when our eyes could not see them both at once. This is a frequent source of disapointment from photographs where one part of the scene was much brighter than another.

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