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The Future of Digital Camera Technology
An anonymous reader writes "CNet News has an interesting look at where digital camera technology is headed now that the megapixel buzzword can be put to rest. From the article: 'In compact cameras, I think that the megapixel race is pretty much over,' says Chuck Westfall, director of media for Canon's camera marketing group. 'Seven- and eight-megapixel cameras seem to be more than adequate. We can easily go up to a 13-by-19 print and see very, very clear detail.'"
There are two other things that can make or break a camera
What seems to slip by the average digital camera buyer, is that megapixels are only relevant in relation to the size of the CCD/CMOS.
SIZE does matter.
BIGGER is BETTER.
Here's a great website that does a basic talk about sensor sizes
If you follow the links you'll learn a lot more about why the sensor & pixel size are possibly more important than just the megapixels offered.
[Fuck Beta]
o0t!
Now that we have cameras of a decent MP maybe we could stop saving as jpeg and instead use a lossless format?
Er, it's called RAW, and all pro cameras and even a lot of pocket cams are capable of using it. This is unrasterized data, so it's about as lossless as it gets (even TIFF is destructive because it rasterizes the images before it's saved).
The problem with RAW formats right now is that they're all proprietary, but this isn't really that big of a deal in practice. Generally speaking, if an image editor supports RAW at all, it will support every major camera. And every camera that supports RAW also ships with its own conversion software (so you can save as whatever format you want).
A little less than a year ago, a graduate student at Stanford gave a talk on light field photography at the University of Washington. The results were extremely impressive. Basically, by inserting an array of microlenses in front of the CCD, you can determine the direction of every ray coming into the camera. You lose resolution, but who needs 8 megapixels anyway? What you DO get is the ability to refocus the image in software, and take photos in low light and still retain a high depth of field.
I highly encourage you to check out his light field photography site, including his galleries, tech reports, and papers. It'll blow you away.
A 13MP RAW image is NOT 39MB. Each 'pixel' in a digital camera only has one color (red, green, or blue typically, sometimes white (Sony), other colors could be used) - it's 8, 10, or 12 bits of data (you won't find 16 bit D/A conversion in a digital camera - it isn't practical and it's well beyond the human eye's ability to discern anyway - though you could argue it would be useful for making very large corrections in saturation or brightness without losing quality) - so stored with no compression at all this is at worst 13 x 12bits = 21.5mb. Add in the fact that you can get a decent compression ration across this data (and your typical 6-8MP DSLRS certainly do) without any loss of data ... maybe 15mb ... or less.
Want to save an image losslessly? Digital SLRs (and some point in shoots) let you save in RAW. Not only is the image saved losslessly, but you can adjust white balance, exposure (within reason), sharpness, and more all after taking the photo!
Want decent optical zooms? SLR lenseshave been available for decades now that range from 8mm to a whopping 1200mm. That's over 100x for you guys used to talking about lenses in terms of "how much zoom" they have. Canon's lens selection.
Want 13MP? The Canon 5D does 12.8. The Canon 1Ds Mark II does 16.8.
Want storage? You can get CF/SD cards as large as 8 gb, and portable hard drives such as the Epson P-2000 made for offloading photos out in the field.
Want to wirelessly transmit photos? The 1Ds Mark II can do it with the WFT-E1A.
Current batteries can let you shoot 2500 shots on a single charge. Spare batteries are cheap and keeping spares in your bag is no big deal.
The thing is that all this technology is already available, but be prepared to spend thousands of dollars for it. If you're looking for all this technology crammed into an everyday point & shoot, give it a few more years.
Instead of more MP, how about better high ISO capabilities? No shutter lag from when you press the button to when the camera takes the picture? How about taking photos at 8fps? Instant-on when you power up your camera? Quicker autofocus? These features are very important, but these too are available on DSLRs, and for a price. Considering how little money you're spending on a point & shoot, they do quite a bit as it is and they'll only get better. The technology is already there and it will eventually find its way down to lower end cameras.
They tell you the camera has 8MP, but "forget" to mention that in reality it has 4M green pixels and 2M of each red and blue. And there's a blurring filter in front of the sensor to reduce moire. So if you photograph fall foliage, your 8MP camera turns into a 2MP one at best. In the BEST case, it's a 4MP camera really, not 8MP.
The only sensor that takes full RGB readings at each sensor location is Foveon, but it suffers from inferior color reproduction and lower ISO sensitivity. It's also pretty low on "real" pixel count - currently at around 3.5MP (which in Canon/Nikon terminology would be called 10MP, because each pixel takes full RGB readout). Foveon pictures are extremely sharp, though, and render textures very well. If they solved their color reproduction issues and upped the pixel count to "real" 5MP - I'd RUN to the store with my credit card in hand to buy a camera based on this sensor.
This really is different from the 640K limit.
The 8MP (or whatever it may end up being) limit is defined by human perception. If no human being can distinguish between a photograph displayed at resolution A and the same photo displayed at resolution B which is greater by some factor, then B is more than adequate and nobody's going to want or need anything beyond that, even if it's techonologically feasible.
In digital audio, we really have reached the limit of human perception, which is probably around 320KB/s, 48kHz. There is probably no technical problem in creating digital audio at 4MB/s, 1Mhz, but you don't hear any audio engineers asking for it.
No similar limit of perception applies to our ability to use and store information.
"A one megapixel camera has one million blue photo detectors, one million red photo detectors and one million green photo detectors."
A 1 MP camera has one million photodetectors, half of which are green, 1/4 red, and 1/4 blue (in most cameras). From this image a one megapixel output image with all RGB components for each pixel is interpolated.
Then there is the issue about bits per pixel. Sensors commonly has 10 or 12 bits per pixel. With a 12 bits per pixel, 13 MP sesor you thus get:
13M * 12 = 156 Mbits = 19.5 Mbytes.
In terms of LCD framing - it has been done - check out the Olympus E330 - they're marketting it as the World's first digital SLR with continuous live view:e 330evolt.asp
http://www.dpreview.com/news/0601/06012606olympus
Personally I prefer to use the viewfinder everytime - but put that down to what I'm used to. I'll bet Olympus will sell alot of these cameras to those like you upgrading from a digital compact who demand the lcd viewpoint. The real sales point for this particular DSLR though is the ultrasonic CCD dust cleaner - I'm really hoping Olympus licences this technology out to other manufacturers... cleaning the CCD every couple of months with a swab and alcohol is something I'd like to lay rest to history - and something that most DSLR manufacturers choose to keep quiet about when selling their cameras...
"In compact cameras, I think that the megapixel race is pretty much over," says Chuck Westfall, director of media for Canon's camera marketing group. "Seven- and eight-megapixel cameras seem to be more than adequate."
Anyone care to guess how long it will be before this quote supplants "640K should be enough for anybody" as the Worst Technology Prediction Ever?
I would say the digital photography field is just a little different than the general computing field, so that really isn't that bad a statement. Your average snapshooter isn't clamoring to print his photos at 36x48 inches nor crop 90% of their image and still expect to have decent resolution. There are a lot of people who are really quite happy with their 3- and 4-megapixel cameras. Having eight or more megapixels is just icing on the cake except for people who actually need or want the extra resolution for various reasons. Even a sharp 3MP photo can often be printed up to 13x19 and still look decent. At the consumer level we really have reached the flattening-out part of the curve in terms of the megapixel race.
What the digital camera world really needs more than ever-increasing megapixels at this point is A) improved dynamic range, B) less noise at high ISO ranges (800-3200+), and C) more cameras with built-in image stabilization. These three things will actually solve real-life problems that people have when taking pictures.
I think dynamic range is the biggest problem. Cameras just aren't capable yet of getting information out of both deep shadows and bright highlights in the same image the way our eyes can. This is confusing to most people and ruins a lot of shots. "Blown" highlights and pure black shadows with no retrievable information are the bane of the digital photography world. Sure, you can shoot RAW and try to manipulate it in Photoshop, but that is really way beyond most people.
Besides dynamic range, most shots are ruined by blur. Either the shutter speed was too slow to stop the movement of the subject, which can be helped a lot by higher ISO capabilities, or the camera was moving too much, which can be helped quite a bit by some built-in image stabilization. Bottom line is, lack of megapixels is no longer the cause of most unacceptable photographs for most people. Except for the pros, it's time to move on to improving other features. I can't really envision a world where regular people are screaming for 32-megapixel compact cameras. Ain't gonna happen.
"They tell you the camera has 8MP, but "forget" to mention that in reality it has 4M green pixels and 2M of each red and blue. And there's a blurring filter in front of the sensor to reduce moire. So if you photograph fall foliage, your 8MP camera turns into a 2MP one at best. In the BEST case, it's a 4MP camera really, not 8MP.
The only sensor that takes full RGB readings at each sensor location is Foveon, but it suffers from inferior color reproduction and lower ISO sensitivity. It's also pretty low on "real" pixel count - currently at around 3.5MP (which in Canon/Nikon terminology would be called 10MP, because each pixel takes full RGB readout). Foveon pictures are extremely sharp, though, and render textures very well."
This utterly fails to take into account how the human visual system works. It also fails to take into account the necessity of filtering when sampling. It also fails to take into account the sophistication of current interpolation algorithms.
The Bayer pattern is actually just about the most efficient layout for capturing images for human perception. I have done dozens of camparison of images capture using the 6Million Bayer arrayed sensors, versus 10.2 Million layered sensors. In the end they are essentially equivalent. The bayer layout allows you to do more with less by taking into account the human image processing system that is heavily organized to toward luminance/green information.
It is utter fanboy nonsense to say a bayer 8MP camera turns into a 2MP when taking fall foliage shots. In any real world situation including fall foliage, an 8MP bayer camera like the Canon 350D will capture more detail than the Foveon sensored SD10 NEW 10.2 Million Pixels (3.4 Mp Red + 3.4 MP Green + 3.4 Mp Blue) (description from Sigma USA page).
As technical bunch we should be able to understand that optimization is sometimes better than brute force. By tilting the sensor toward green, it is tilted toward luminance capture and tilted toward the way humans view details.
In thousand of empirical comparison online, parity is reached when there is an approximately equal number of green sensors. So 6MP bayer (3MP green) where approximate equal to 10.2MP foveon chip with ~3MP green. Actual 10MP bayer (5MP green) cameras like Nikon D200 easily capture much more detail than Sigmas 10.2MP chip.
The sampling issue. The Sigma has no filter to prevent undersampling artifacts. It doesn't suffer from colour moire artifacts, but it has plenty of luminance moire. See here for an ancient comparison of the 6MP Canon D60 and the 10.2MP Sigma SD9:
http://www.wfu.edu/~matthews/misc/DigPhotog/alias/
Scroll to the photo comparison at the end. The only extra detail in the Foveon based image is Aliasing errors. These are extremely prevalent in Sigma images with sharp diagnals, or repeating patterns beyond the Nyquist frequency of the sensor.
In the end, bayer is an excellent engineering optimization to do more with less. The real comparison that counts is how does it compare with film. A 6mp Bayer sensor in an DSLR is already better than 35mm film. By 10MP it is significantly better.
The other important factor is how the bayer DPI translates in the printed image. I have found that around 240 DPI is close to optimal image quality. So a Canon 350D with a 3456 pixel image width can produce a superb quality image about 14 inches wide. Be aware this is not to say you can't print larger. This is highly subjective depending on source material, but with detailed material this is the point where I consider that you would be hard pressed to notice any improvement from more pixels.
So even if you only want to print 13"x19" I think you could still see improvement from more pixels if printing detailed subjects like landscapes.
You can argue the quandry of subject, material and view distance till the cows come when considering viable prints size. I mere wish to express what I consider the
If you're referring to dynamic range the same as one does in film, that is, seven "stops", then simply adding more bits to the A/DC doesn't get you there. You need better sensors, as a pixel well has characteristics too. Namely a noise floor and a ceiling that saturates with too much light. Mess with the ceiling in an attempt to prevent early saturation, and you kill low-light sensitivity. Dive too deeply into the floor, and you have noise issues.
The standard analogy is a set of stairs five feet tall. I can have each stair be a foot high, or each stair be 6" high. With the later, I have more "bits", and be more accurate in terms of height (color), but the set of stairs will still only be five foot tall. In film terms, I will have captured only five "stops" of data, no matter how finely I divide them up.
That's why you see such oddball attempts at sensor design, like Fuji's SuperCCD, where one sensor in each matrix is harder to saturate, and as such is dedicated to pulling more detail out of the highlights.
Now in that case, you do need more bits to represent the data, but not in the way normally thought of. A 10-bit converter will still map the white point to 0xFFFF and the black point to 0x0000, and get the job done, but as range increases that leaves you with larger gaps (posterization) between individual points in the range. A 12-bit A/DC will fill in those gaps and give you smoother transitions.
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