Digital Chips

Digital Chips Ramble

In other rambles, I've explained that I still shoot in the analog world with aging equipment. No longer, I suppose, may I quietly chuckle to myself at 'older guys on vacation' (calf-high black socks, business shoes and shorts) shooting with their ancient leather-clad cameras. But for the wacky attire thing, I'm becoming one of those antique-toting photographers, so I need to be a bit more careful about what I laugh at.

I do have an interest in the new technologies available to photographers, but by no means should I be considered a 'technician' of any sort. One technology I am most intrigued currently is the Foveon X3 imaging chip. As an alleged 'marketing guru' (some days my boss would disagree!) for the life of me I cannot figure out why the pro-sumer and professional photographic markets are not clamoring for this chip in their equipment.

Here is my understanding of how a 'normal' CCD or CMOS chip captures
an image. Light enters the lens focused onto the surface of the chip. The chip is made up of millions of pixels. The pixels are generally clustered in groups of three, each pixel in the cluster responsible for 'reading' red, blue or green light. The input from all these pixels is combined and electronically processed into the image you see on the viewscreen or capture to the memory card.

By my understanding, if you have a 6 megapixel chip (1 megapixel equal to 1 million pixels), 2 million pixels pick up red, another 2 million pick up blue and another 2 million pick up green light. In other words, shooting just a blank red wall your 6 megapixel chip will use only 2 million pixels, the other 4 million pixels worth of color information is 'interpolated' by the camera's software.

Foveon has developed the ability to 'stack' the Red, Green and Blue reading pixels, so the chip is layered, just the way color film is layered. So with the Foveon X3 chip, shooting a blank red wall will use all 6 million pixels. To my mind (and Foveon's message) the X3 chip provides 3X the resolution of standard chips with the same megapixel rating.

More megapixels results in a higher quality image, especially when larger prints are the desired result. This is similar to the image difference between, perhaps, the old 110 cameras and 35mm film, or with higher pixel counts comparing to 120 format film. Thus the 3 megapixel Foveon X3 chip is very intriguing to me as it apparently provides the same image quality of a 9 to 10 megapixel chip.

Some photographers I've spoken with think Foveon shots appear a bit 'soft'; something like the lower contrast of 'portrait' type films. Personally I think the 'softness' comes from a lack of 'interpolation' required to fill-in the spaces between pixel clusters in a 'normal' chip. Again, I am not a technician so don't quote me on this! I've been wrong before, so would welcome your correction.

On the other hand, if soft contrast is a problem with a digital camera, that is certainly easy enough to fix with the photo editing software of your choice.

See for yourself how photographs taken with the Foveon chip look. Browse over to www.foveon.com and see if their sample shots appeal to your eye.

As for myself, I look forward to the time the personal budget allows an upgrade to a D-SLR. When the time comes, I'll be taking a serious look at the Sigma cameras (with the Foveon chip) and at other manufacturers who pick-up this exciting technology in the interim.