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SE plans to impove K750 in July/August |
bico
Joined: May 19, 2003
Posts: > 500
From: Stockholm, Sweden.
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By searching for CMOS vs CCD by using Google Search you can find some quite useful information. A brief summary follows.
CMOS vs CCD and the Future of Imaging (Kodak Research) by Kodak
- Both CMOS and CCD imagers are manufactured in a silicon foundry
- Developed in the 1970s and 1980s specifically for imaging applications, CCD technology and fabrication processes were optimized for the best possible optical properties and image quality. The technology continues to improve and is still the choice in applications where image quality is the primary requirement or market share factor.
- This (the CCD) architecture produces a low-noise, high-performance imager. That optimization, however, makes integrating other electronics onto the silicon impractical. In addition, operating the CCD requires application of several clock signals, clock levels, and bias voltages, complicating system integration and increasing power consumption, overall system size, and cost.
- A CMOS imager, on the other hand, is made with standard silicon processes in high-volume foundries. Peripheral electronics, such as digital logic, clock drivers, or analog-to-digital converters, can be readily integrated with the same fabrication process.
- This architecture allows the signals from the entire array, from subsections, or even from a single pixel to be readout by a simple X-Y addressing technique—something a CCD can’t do.
- The biggest opportunities for CMOS sensors lie in new product categories for which they are uniquely suited. Keys to their success are
- Lower power usage
- Integration of additional circuitry on-chip
- Lower system cost
Such features make CMOS sensors ideal for mobile, multifunction products ...
- CCDs have been mass-produced for over 25 years whereas CMOS technology has only just begun the mass production phase. Rapid adoption was also hindered because some early implementations of these devices were disappointing: they delivered poor imaging performance and poor image quality.
- ... the current sensor market divides itself into two areas: the high-performance, low-volume branch, and the low-cost, high-volume branch. In the high-performance branch are applications that will continue to be dominated by CCD technology, but CMOS technology will find market share too, especially for lower cost or more portable versions of these products. The second area is where most of the CMOS activity will be. Here, in many applications CCD sensors will be replaced with CMOS sensors. These could include some security applications, biometrics and most consumer digital cameras.
- Most of the growth, though, will likely come from products that can employ imaging technology—automotive, computer video, optical mice, imaging phones, toys, bar code readers and a host of hybrid products that can now include imaging. These kinds of products will require millions of CMOS sensors.
CCD vs. CMOS by Dalsa
- CCD (charge coupled device)
- CMOS (complementary metal oxide semiconductor)
- CCDs and CMOS imagers have unique strengths and weaknesses that make them appropriate to different applications. Neither is categorically superior to the other ...
- In a CCD sensor, every pixel's charge is transferred through a very limited number (often one) of output nodes to be converted to voltage, buffered, and sent off-chip as an analog signal. All of the pixel can be devoted to light capture, and the output's uniformity (a key factor in image quality) is high.
- In a CMOS sensor, each pixel has its own charge-to-voltage conversion, and the sensor often also includes digitization circuits, so that the chip outputs digital bits. These other functions reduce the area available for light capture, and with each pixel doing its own conversion, uniformity is lower. But the chip requires less off-chip circuitry for basic operation.
- CCDs have been the dominant solid-state imagers since the 1970s, primarily because CCDs gave far superior images with the fabrication technology available.
- Only recently has semiconductor fabrication advanced to the point that CMOS image sensors can be useful and cost-effective in some mid-performance imaging applications.
- CCDs offer superior image performance (as measured in quantum efficiency and noise), and flexibility at the expense of system size. They continue to rule in the applications that demand the highest image quality, such as most industrial, scientific, and medical applications.
- CMOS imagers offer more integration (more functions on the chip), lower power dissipation (at the chip level), and smaller system size at the expense of image quality and flexibility. They are well-suited to high-volume, space-constrained applications where image quality is not paramount, such as security cameras, PC peripherals, toys, fax machines, and some automotive applications.
- CMOS cameras may require fewer components and less power, but they may also require post-processing circuits to compensate for the lower image quality.
- The money and attention concentrated on CMOS imagers means that their performance will continue to improve, eventually blurring the line between CCD and CMOS image quality.
- ... for the forseeable future, CCDs and CMOS will remain complementary. Each can provide benefits that the other cannot.
Feature and Performance Comparison
| Feature | CCD | CMOS |
| Signal out of pixel | Electron packet | Voltage |
| Signal out of chip | Voltage (analog) | Bits (digital) |
| Signal out of camera | Bits (digital) | Bits (digital) |
| Fill factor | High | Moderate |
| Amplifier mismatch | N/A | Moderate |
| System Noise | Low | Moderate to High |
| System Complexity | High | Low |
| Sensor Complexity | Low | High |
| Camera components | PCB + multiple chips + lens | Chip + lens |
| Relative R&D cost | Depends on Application | Depends on Application |
| Relative system cost | Depends on Application | Depends on Application |
| Performance | CCD | CMOS |
| Responsivity | Moderate | Slightly better |
| Dynamic Range | High | Moderate |
| Uniformity | High | Low to Moderate |
| Uniform Shuttering | Fast, common | Poor |
| Uniformity | High | Low to Moderate |
| Speed | Moderate to High | Higher |
| Windowing | Limited | Extensive |
| Antiblooming | High to none | High |
| Biasing and Clocking | Multiple, higher voltage | Single, low-voltage |
Digital Camera Sensor Technology: CMOS vs. CCD by ExtremeTech
- All CCD cameras use interpolation to create images. For example, a 3 megapixel digital camera only has 750,000 red, 750,000 blue, and 1.5 million green pixels, but the camera's on-board processor generates a 3 million pixel RGB color image by interpolating the data from each neighboring pixel.
- CMOS sensors have several advantages over CCDs. They use only 1/5 to 1/10 as much power as CCDs, making them a good choice for battery-powered cameras. CMOS sensors are made using the same techniques and equipment as more familiar CMOS circuits like CPUs and RAM memory, so they cost less to produce than CCDs, which require specialized fabrication equipment.
- Each pixel in a CMOS sensor has its own amplifier circuit, so the signal amplification is performed before the image is scanned.
- ... CMOS sensors often contain additional image processing circuitry (including analog-to-digital converters and JPEG compression processors) directly on the chip, making it easier and faster to retrieve and process the picture information. This results in a lower chip count, increased reliability, reduced power consumption, and a more compact design.
- A key problem in older CMOS sensors was that some pixels often had more or less sensitivity than their neighbors. This unevenness translates into noise.
Image Sensor Technology: CMOS vs. CCD by Hewlett Packard
- ... CMOS components are fabricated in mainstream silicon foundries, resulting in significant cost reductions, process line improvements, and a higher level of circuit integration on the chip.
This on-chip circuitry enables CMOS image sensors to achieve a significant advantage in functionality over CCDs. The result? A more compact system that decreases defects, increases reliability and reduces the need for peripheral support chip packaging and assembly, further reducing cost.
- Stated simply, CMOS sensors consume much less power than that of similar CCD sensors—at least 10 times less, in fact. This advantage is particularly important for applications such as digital cameras, PC videocameras, laptop computers, cellular phones and toys.
- Unlike CMOS components, CCD systems require multiple 5-15 V power supply levels and voltage regulators for operation. CMOS typically uses a single, 3.3 volt (or 5 volt supply), increasing power supply efficiency.
- With CMOS, signal processing can be integrated directly on the chip.
- Higher yields and less susceptibility to defects make CMOS a lower cost technology than CCD for image sensors. Fewer parts, a smaller form factor, and higher reliability in the end product system mean cost savings to the systems manufacturer.
- CCDs rely on a process that can leak charge to adjacent pixels when the CCD register overflows; thus bright lights “bloom” and cause unwanted streaks in the image. CMOS architecture is inherently less sensitive to this effect.
- In addition, smear—caused by charge transfer in the CCD under illumination—is non-existent with CMOS.
The choice between CMOS- and CCD-circuitry is obviously neither black nor white.
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/bico
[ This Message was edited by: bico on 2005-05-29 21:49 ] | |
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Someone1018
Joined: Dec 02, 2004
Posts: 18
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Very helpful and interesting read. thanks bico |
Marcus_129
Joined: Aug 19, 2003
Posts: 136
From: sweden
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Quote:
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On 2005-05-26 14:10:28, gbrooks3 wrote:
@Marcus_129
What the Hell is wrong with you? Dont talk to someone you dont know like that! Comeback when you have something useful to say! You think that i have well over 1000 posts at esato and i am not familiar with the concept of Upgrades? hahahaha, joker. 
I was just saying that before the this ugrade the K750i was not a great phone in my opinion. Now with these improvements the phone is definatley worth buying.
I dont know what you interpreted that as! Seems simple to me.
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I can´t see that´s it anything wrong with me. Only get so sick and tired of you negative people. Don´t know what you get out of complaining on everything?
K750 is a great phone as it is and when the update service gets up it will become even better. Even if there´s a update in hardware coming the K750 isn´t a bad phone. And many of you complaining that it´s coming a update were complaining that it took too long with a successor from K700 |
K750i
Joined: May 20, 2005
Posts: 13
From: Malaysia
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@bico,
interesting info there...but the conclusion is what? CCD or CMOS? which one is the better one? or is it no definite answer to it? |
aydahm
Joined: Jun 14, 2003
Posts: 218
From: Turkey
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The comparison thread is really good and informative, but what we should really know is what difference will it make in a 2MP phone? In other words, for the K750, in what conditions will each system have an advantage or disadvantage? |
bico
Joined: May 19, 2003
Posts: > 500
From: Stockholm, Sweden.
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@K750i: Which technology is the better one? The definite answer is that it's certainly not definite. Both technologies has its pros and cons.
My personal conclusion is that it doesn't really matter that much. The camera in the K750i phone is more than good enough. Especially considering it's a phone with a built in camera, not a camera with a builtin phone.
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/bico
[ This Message was edited by: bico on 2005-05-30 22:13 ] |
rabvtec
Joined: May 29, 2005
Posts: 19
From: Edinburgh
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Jeez! What a loada heave-ho over picture quality and CCD v CMOS! I may be a noob to this forum but I've many years in others including many on digicams ...
As bico says, we got to remember this is a phone with a camera and NOT the other way around! IMHO, as the first candy bar phone to sport a 2meg AUTOFOCUS camera, SE have done a remarkable job.
Sure, there will be firmware to 'improve' this and 'fix' other bugs, but what piece of electronic hardware these days doesn't?! (my PC's NVidia card gets 'fixes' AT LEAST once a month).
Enjoy the phone, learn the phone ... and have FUN with the phone! |
kooki
Joined: Jul 13, 2004
Posts: 381
From: bangalore, india
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well i dunno much about digi cams but what im told is ccd makes sharper images...and cmos technology is older...recently cmos has picked up in high end digi cams.
i called up a few people too and it is true that the k750 will have a ccd sensor soon
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jmbillings
Joined: Sep 28, 2002
Posts: 196
From: Oundle, UK
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tbh I dont think the tiny lenses on these cameras allow the full quality to come through. My "real" digicam is only 2Mp as its a few years old, and while the pics I have seen people post from the K750 are good, they aren't a patch on those from a proper camera. A lot of this is down to the small lens, it will never focus light as accurately and without colour splitting as much as a decent lens. Its the same as those cheap chuck-away cameras with a 35mm film in them - my SLR gives much better results simply because the lens is of higher quality.
CCD may be technically better than CMOS, but I dont think the difference will be enough to worry about - look at the differences in the pictures people are taking with the current K750, some are fantastic, some are not so great!
Sleep well people!
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bico
Joined: May 19, 2003
Posts: > 500
From: Stockholm, Sweden.
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@kooki: I'm sorry to tell you, but according to some sources the CCD technology is older than the CMOS technology:
Quote:
| CCDs have been mass-produced for over 25 years whereas CMOS technology has only just begun the mass production phase. |
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For further information, take a look at this post, posted earlier in this thread.
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dave_uk
Joined: Mar 06, 2003
Posts: > 500
From: London, UK
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As someone who knows next to nothing about digital imaging, having merely read the information in the comparison below. It seems fairly obvious that CCD is superior to CMOS, and that the justification for CMOS is that it is:
a)more flexible
b)cheaper
c)lower on power consumption, but and there is no getting away from this,
d) poorer in image quality.
It is clear that CMOS is therefore attractive to mobile device manufacturers, as it allows easier integration into their systems and consumes less power (not to mention lower production costs). However, equally, it is clear that the resulting images are compromised.
Having said this, it seems unlikely that  would take the decision to implement this cheaper, more efficient, technology (with it's obvious benefits to them) and then decide to increase the manufacturing cost and upset the market. It makes no commercial sense and I would therefore conclude that rumours of this upgrade must be false (though that would not rule out a different model - say the S700i replacement - using a CCD sensor).
But, as I said, I know next to nothing about digital imaging...
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bico
Joined: May 19, 2003
Posts: > 500
From: Stockholm, Sweden.
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As dave_uk indicates: CCD technology in S700! CCD technology in S750?
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jofullalove
Joined: May 25, 2005
Posts: 28
From: Lancashire
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I think that my k750i camera is really really good. The quality is brill. CCD may be an improvement, but it will only be slight plus the ccd version will probably hike up the price a bit. If i were you guys contemplating waiting for an updated version (assuming there will definately be one...) i wouldn't bother. |
ares
Joined: Dec 11, 2003
Posts: > 500
From: Coimbra, Portugal
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Quote:
| look at the differences in the pictures people are taking with the current K750, some are fantastic, some are not so great! |
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same is true with ANY camera
K750 CMOS camera vs Minolta and Canon CCD cameras test here
Bottom line: i´ll buy a k750 once i can, despite having a CMOS or a CCD - has an amateur photographer i´m already satisfied with what i see right now
http://www.lesnumeriques.com/news_id-584.html
Not much difference actually...SE done a remarkable job with this CMOS
I figure CCD will only be real noticed in low light photos and even there i don´t know if improvemente is gonna be all that big (look at s700 low light photos)
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k700i + hbh 600
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[ This Message was edited by: Arez on 2005-06-02 16:26 ] |
Krubach
Joined: Dec 05, 2002
Posts: > 500
From: Sunny Portugal! :)
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@Arez
May i say that the comparison shown on that website are not correct since ALL photos in the comparison are pictures taken inside a room and doesn't have photos with natural light.
Something is missing...
Can someone please edit the first post and change the "impove" to "improve"... if i got it right... :?
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[ This Message was edited by: Krubach on 2005-06-03 10:12 ] | |
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Posted: 2005-05-29 21:14
