Apple has a knack for dropping weird and wonderful technologies into our laps — everything from
IPS displays to
MEMS gyroscopes, and now, back-illuminated sensors. Don't know what that last one is? You're not alone. The technology, introduced by Sony
almost two years ago today, is relatively new, and has found fairly limited thus far. Yet, that's something Apple is looking to change.
With the
iPhone 4's new 5 Megapixel camera, Steve Jobs promised many things, from
increased photon collection to pixel maximization — things that sound great on paper, but do little to enlighten the average Joe. What matters is how well the new iPhone performs, and what you can expect from your pictures. There's no doubting that a back-illuminated sensor will produce better pictures than the iPhones of old, but the real question is, by how much?
A camera sensor is built like a sandwich, and a back-illuminated structure alters how that sandwich is constructed. Traditionally, light photons would pass through a layer of metal wiring before being collected to produce an image. This process meant that not all photons would make it through successfully, darkening the image. By placing that metal wiring behind the collection layer, no photons are lost in the process.
Note how a back-illuminated sensor leaves all the photons intact. That means a brighter image.
Already, you can probably guess the outcome this will produce. More photons means more light, and a brighter image can be captured over the same amount of time when compared to traditional means. As a result, a higher sensitivity to light is one of the big selling points of back-illuminated sensors, and an area in which cell phone cameras have often under performed. In testing, Sony found the technology offered nearly
twice the sensitivity of its traditional CMOS sensors, while Toshiba's implementation
produced similar results as well.
In the case of the iPhone 4, the technology should offer a huge improvement in picture quality — perhaps a two-fold increase in brightness compared to previous models, if Sony's tests are any indication. This is huge for low-light shooting, and should make a big difference in terms of video capture as well.
But
as CNET points out, a better sensor doesn't necessarily mean a better shooting experience. Image processing could still be slow, even with that beefy A4 chip, and the plastic lens does a lot to degrade your picture's quality. However, there's no doubting some of the photos demoed during today's unveiling were impressive, and real-world performance remains a mystery until the device is in our hands. If image stabilization is included as well —
and the possibility is there — we could have one serious camera phone later this month as far as mobile shooting is concerned.
Images via Apple, Sony.
