Warm Southern Breeze

"… there is no such thing as nothing."

The ONLY digital camera that CANNOT shoot color is…

Posted by Warm Southern Breeze on Friday, May 25, 2012

Huh?

You mean there’s a digital camera that CANNOT make color photographs?

Yup.

Not to worry.

You probably won’t buy it.

Besides… it’s nearly US$8000.

Unless you’re an artsy fartsy fancy schmancy pho-tograffer type… and in which case, you probably don’t have a lot of munny anyway. Fo-to-graffers don’t make a whole lot of munny.

You know… they’re the starving atisté kind.

But, on the upsid3… the REAL matter is the development of sensors, and how they perceive and are sensitive to light.

For all the bazillion-dollar cameras that can see in the dark, and blah, blah, blah… there has NEVER EVER been a camera that has EVER come close to the human eye.

Seriously.

Think about it.

Your $8000 Nikon or Canon, or Leica cannot in any way come close to accurately reproducing what your eye is capable of seeing.

Your eye can see detail in highlights AND in shadows… without PhotoShop.

Your Canon or Nikon or Leica cannot.

Try to take a “well-exposed” photograph in the dark.

Your camera needs a flash, doesn’t it?

Your eyes don’t.

Yeah, sure… digital cameras can see the infrared spectrum of light, whereas your eyes can’t, and that’s pretty kewl, to be certain. But you CAN see what the sensors reproduce, right?

Again, to be certain, the sensors on a digital camera are in NO WAY as versatile and as sensitive as your eyes.

Colour-blind Digital photography?

May 24th 2012, 6:31 by M.H. | SEATTLE

Leica M Monochrom

Leica M Monochrom

IMAGE sensors at the heart of digital cameras are naturally colour-blind. Each of their millions of tiny photo-sensitive elements measures only the intensity of incoming light, not its wavelength. In order to record colour information, an array of microscopic filters is placed in front them. A quarter of the elements have a red filter, a quarter have a blue filter and the remaining half, green filters.

This arrangement, first devised by Bryce Bayer of Kodak, reflects the physiology of the human eye, which is more sensitive to light in the green part of the spectrum. Software inside the camera then reconstructs the original scene through a process known as demosaicing. Essentially, it takes a guess at the colour of each pixel based upon that of its neighbours.

This procedure can be problematic, however. Fine details in the original are inevitably lost, especially at shapes’ edges, robbing the final image of sharpness. False colours can pop up, ugly interference patterns emerge, caused by a clash between the repeated structure of the filter and patterns in the scene being captured. Noise (random speckling caused by electronic fluctuations in the sensor’s circuitry) is also accentuated. Crucailly, all this number crunching takes time, causing a delay before the camera is ready to shoot again. It would be preferable, then, if cameras could somehow do without the Bayer filters.

That is just what a new camera from Leica, the M Monochrom, has done. Without a Bayer filter on its 18 megapixel sensor, every photosite records the actual intensity at that point. According to Leica, this creates images that are twice as sharp as those from its siblings in the M series. Noise is less noticeable, too. And because there is no filter obscuring light from reaching the sensor, the camera can shoot in darker conditions, giving photographers two more of what they dub f-stops, and with them more flexibility in selecting exposure settings, says Jesko von Oeynhausen of Leica. The results are stunning.

There is, however, a rub. The M Monochrom is the only digital camera on the market that cannot shoot colour images. Working exclusively in black and white might appeal to Leica’s well-heeled, arty customers. But the M Monochrom is unlikely to make much of an splash with mainstream snappers, especially priced at $7,950 (without a lens).

Other camera manufacturers are working on less drastic ways around the limitations of Bayer arrays. Fujifilm has devised a semi-random method of arranging colour filters that reduces both interference and colour artefacts. Foveon sensors, which can be found in Sigma digital single-lens-reflex (SLR) cameras, cleverly exploit the fact that different wavelengths of light penetrate silicon to different depths. The chips’ top layers detect short-wavelength blue light, green light is recorded in the middle, while the longer-wavelength red light travels all the way to the bottom of the stack.

Perhaps the most modern solution is to simply throw more pixels at the problem. Nokia‘s upcoming 808 PureView mobile phone boasts a 41 megapixel image sensor, sporting a traditional Bayer filter. In the past, such a high-resolution sensor would have been prohibitively expensive; now it is cheap enough to use in a phone that is likely to be offered free with a contract.

The idea is not for the Nokia 808 to capture images at its maximum resolution, which would result in unnecessarily massive files. Rather, it is to deliver “oversampled” images of just 5-8 megapixels. Oversampling combines multiple red, blue and green pixels clustered close together into a single superpixel, then builds up a high-quality image from these. Not only does this approach naturally supress visual noise by averaging out random errors in individual pixels, it also eliminates the need for demosaicing.

As with Leica’s Bayerless M Monochrom, oversampling a high-resolution sensor promises to create sharp, low-noise images. Unlike Leica, Nokia has not had to take a step back in time to achieve it.

www.economist.com/blogs/babbage/2012/05/digital-photography

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