The Digital Sensor: Part 2

Fast Forward

There was a time not long ago when casual photographers selected a point-and-shoot digital camera. They were reasonably priced, new models were everywhere, and the price for something even better was extremely high. Technology development in the digital camera arena, as in every other area of consumer electronics, has pushed the price of digital sensor technology lower and lower, and that is a trend that will undoubtedly continue. At the same time speed and quality have continued to evolve at a dramatic pace.

As a result the digital point-and-shoot has moved downstream, as it is hard to convince anyone to buy an expensive point-and-shoot when you can buy a capable Digital SLR today for as little as $400. When 10MP sensors burst onto the DSLR scene about two years ago the price of admission was $1000. Today that $400 to $600 DSLR has a 10MP sensor.

With lower prices and more capabilities, the Digital SLR is clearly today's photo market leader. The explosive growth in this segment is bringing new first time buyers into the DSLR market, some moving up from point-and-shoot and some choosing one of today's more reasonable DSLRs as their first camera.

With so many new users in the DSLR market it should come as no surprise that DSLR makers are trying to make DSLRs easier to use. There is one trend to make the DSLR more comfortable for those moving up from point-and-shoot with features they already know like Live View. Another trend is to give first time users a greater chance of success by combining optical (in-lens) or mechanical (in-body) IS (Image Stabilization) with the cheaper, slower DSLR lenses. This actually gives new users a better chance of capturing decent pictures in everyday lighting conditions. If you wonder how universal this has become you only need to look at the cheap optical IS lenses Canon and Nikon now supply with their entry D60 and XSi models.

It is easy in examining technology to forget about buying motivations. Lower price is increasing Digital SLR demand, but the reason new buyers select a Digital SLR is because they want better quality pictures than they can get with a point-and-shoot camera. The same reason applied in the first SLR explosion in the 70’s and 80’s when new buyers chose film SLRs instead of 110 point-and-shoots. 

The quest for improved quality may be even more relevant in the digital camera era than it was in film. Film was a common denominator in film cameras, but in digital cameras film and the processing lab have moved inside the camera. This makes the digital sensor the most important factor in the imaging quality of today’s digital cameras. Different manufacturers have different optic lines to mount on this analog-to-digital computer. All the big brands have different expertise and interpretations of the analogue capture to digital image conversion process. In the end, however, it all begins with the digital sensor. 

The digital sensor is the reason the tiny sensor in point-and-shoot cameras has a limited speed range and why the images can never be as good as a Digital SLR. Even if you mount the world’s best optics on a point and shoot you are still quality bound by the digital sensor capabilities. For today the resolution limits of the small P&S sensors seem to have been reached. Somewhere around 8 to 10MP we are finding that higher resolution also generally means higher noise and lower sensitivity. That is the reason the growth and development has moved to the larger sensors of the DSLR.

No doubt this roadblock will be passed with advancements in sensor technology, but today more than 8MP of clean resolution and usable sensitivities greater than ISO 400 are rare indeed in the compact camera market. APS-C sensors in Digital SLRs, however, seem to be getting better and better at higher and higher sensitivities and ever increasing resolutions. Skeptics are already screaming we are going too far with14MP sensors, but they forget that the smallest 4/3 sensor is still a ten times larger area than the largest compact sensor. There is still a lot of room for growth in resolution.

The other complaint you often hear is that lenses are finally reaching resolving limits with higher sensor resolutions. That is certainly true with the cheap lenses that were the staple of the developing SLR market. Most any piece of glass was fine on a 6MP sensor, but 12 to 14 megapixels demand quality optics. This will challenge the industry to produce higher resolving optics at ever cheaper prices as digital cameras approach and pass the resolving power of 35mm film. The industry has been coasting for far too long in the low demands of the developing digital SLR market. Innovative high-quality optics will emerge as we are already seeing in some of the remarkable new kit lenses developed for the higher resolution sensors.

Serious photo hobbyists will also be facing difficult decisions today and even more so in the near future. The cost of larger and larger sensors has been dropping rapidly; and CMOS sensor development from all the sensor manufacturers is also a factor in lowering costs and increasing resolution. Like it or not Canon and Nikon have already begun segregating their SLR line into full-frame and APS-C sensors. Those who wondered  why Sony was introducing mainly full-frame lenses will finally get their answer later this year with Sony's 24.6MP full-frame flagship model.

Full-frame has been mainly the domain of Professional photographers up to this point. Full-frame will likely still be targeted at the top of the digital SLR market by Canon/Nikon/Sony so your favorite APS-C camera and lenses does not appear to be in any real danger of becoming obsolete.

Players like Pentax and Samsung seem positively locked into APS-C with no full-frame peeking around the corner, and Olympus has fought too hard for credibility with 4/3 to start promoting full-frame. Similarly Nikon, Canon, and Sony will define the full-frame as Pro and the rest of their line as prosumer and entry. However, technology will march on and new and cheaper full-frame sensors will be introduced. With the new sensors will come new camera models built around those sensors.

Those who doubt that only have to look back at the development history of the digital sensor. When 1 megapixel was reached Nikon ran huge spreads of carefully produced photos created with their expensive point-and-shoot digitals showing that digital had arrived and photographers had all they could possibly need in that 1 megapixel sensor. We know better today only because the digital sensor continued its development.   You can be certain that, like CPUs in computers, the digital sensor of tomorrow will be different in ways we can only imagine today.  

For some readers the joy of the process is the technology ride. For others the utility of the ever evolving digital sensor and processing electronics is the main thrust. We can only say there is plenty of joy in the Digital SLR market for everyone. 

Slapping optics on an Analog-to-Digital imaging computer is an exciting concept for geeks. We sincerely hope The Digital Sensor articles have given you more insight into how digital cameras work and a better understanding of the technology issues facing Digital Camera development.