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Sensor noise: Nikon D200 versus Canon S70
I've completed two new digital camera analyses:
The Nikon D200 Digital Camera: Sensor Noise, Dynamic Range, and Full Well Analysis http://www.clarkvision.com/imagedeta...ion-nikon-d200 Compare those results to a small pixel P&S camera: The Canon S70 Digital Camera: Sensor Noise, Dynamic Range, and Full Well Analysis http://www.clarkvision.com/imagedeta...tion-canon-s70 I've included comparisons of the above results in some new figures (3b, 6 and 7) and discussion on this page: Digital Cameras: Does Pixel Size Matter? Factors in Choosing a Digital Camera http://www.clarkvision.com/imagedeta...el.size.matter Roger |
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Sensor noise: Nikon D200 versus Canon S70
"Roger N. Clark (change username to rnclark)" writes:
I've completed two new digital camera analyses: The Nikon D200 Digital Camera:... The Canon S70 Digital Camera:... Cool. Do you want similar data from other cameras? |
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Sensor noise: Nikon D200 versus Canon S70
Roger N. Clark (change username to rnclark) wrote:
I've completed two new digital camera analyses: The Nikon D200 Digital Camera: Sensor Noise, Dynamic Range, and Full Well Analysis http://www.clarkvision.com/imagedeta...ion-nikon-d200 Compare those results to a small pixel P&S camera: The Canon S70 Digital Camera: Sensor Noise, Dynamic Range, and Full Well Analysis http://www.clarkvision.com/imagedeta...tion-canon-s70 I've included comparisons of the above results in some new figures (3b, 6 and 7) and discussion on this page: Digital Cameras: Does Pixel Size Matter? Factors in Choosing a Digital Camera http://www.clarkvision.com/imagedeta...el.size.matter Roger Roger, How do all the Canon cameras manage such low read noises? I did ask once before, and you said you also found it strange that they managed to reduce read noise to such low levels for their CMOS sensors. Well, it's equally low for this compact, which has a CCD. Any idea how this can happen (except by some very effective image processing before doing anything else to the raw data)? Cheers. |
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Sensor noise: Nikon D200 versus Canon S70
"acl" wrote in message ... SNIP How do all the Canon cameras manage such low read noises? http://web.canon.jp/Imaging/cmos/technology-e/noise_reduction.html SNIP Any idea how this can happen (except by some very effective image processing before doing anything else to the raw data)? There may be some specific noise suppression in the DIGIC processor as well, but at least it is not obvious (apart from the absence of noise). -- Bart |
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Sensor noise: Nikon D200 versus Canon S70
Hello Bart,
Bart van der Wolf wrote: "acl" wrote in message ... SNIP How do all the Canon cameras manage such low read noises? http://web.canon.jp/Imaging/cmos/technology-e/noise_reduction.html Right, but the S70 has a CCD, so it's not what is described there. The S70 has extremely low read noise (as measured by Roger) for a CCD. It's lower than most CCDs for scientific applications (I asked people at the place where I work who deal with these things about usual read noise levels, as I personally am clueless in practical matters). SNIP Any idea how this can happen (except by some very effective image processing before doing anything else to the raw data)? There may be some specific noise suppression in the DIGIC processor as well, but at least it is not obvious (apart from the absence of noise). I didn't mean the same sort of thing that Neat Image (say) does. But I always had trouble understanding how else they get the read noise so low (I didn't have quantitative data, but looking at high ISO images in the shadows it looked quite incredible). I think it is clear that some very clever and effective processing is taking place. At least, I can't think of any other explanation. But this is still strange, how is it possible that Canon come up with such an algorithm but nobody else? |
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Sensor noise: Nikon D200 versus Canon S70
Paul Rubin wrote:
"Roger N. Clark (change username to rnclark)" writes: I've completed two new digital camera analyses: The Nikon D200 Digital Camera:... The Canon S70 Digital Camera:... Cool. Do you want similar data from other cameras? Yes, I would. Others are doing these analyses too, and I've collected the information and summarized it in Tables 1-4 he http://www.clarkvision.com/imagedeta...ignal.to.noise But most efforts are by amateur astronomers trying for cameras more suited to low light work. I would be interested in filling in more data between the 2.3 and 6 micron pixel range, and if any camera comes out much below 2.3 microns. A requirement is that the camera must put out raw data. Taking the data is pretty easy. Another requirement is that there is software to get the linear raw data from the raw file. Then it takes me several days of work to analyze and write it up. Roger |
#7
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Sensor noise: Nikon D200 versus Canon S70
acl wrote:
Hello Bart, Bart van der Wolf wrote: "acl" wrote in message . be... SNIP How do all the Canon cameras manage such low read noises? http://web.canon.jp/Imaging/cmos/technology-e/noise_reduction.html Right, but the S70 has a CCD, so it's not what is described there. The S70 has extremely low read noise (as measured by Roger) for a CCD. It's lower than most CCDs for scientific applications (I asked people at the place where I work who deal with these things about usual read noise levels, as I personally am clueless in practical matters). Canon's S60 camera has much worse read noise, so they have certainly done something different on the S70. One trick used in CCDs is to read the signal multiple times effectively averaging the read noise toward zero. I don't know if Canon does some trick like that (the web page you reference does imply multiple reads). Any idea how this can happen (except by some very effective image processing before doing anything else to the raw data)? There may be some specific noise suppression in the DIGIC processor as well, but at least it is not obvious (apart from the absence of noise). I didn't mean the same sort of thing that Neat Image (say) does. But I always had trouble understanding how else they get the read noise so low (I didn't have quantitative data, but looking at high ISO images in the shadows it looked quite incredible). I think it is clear that some very clever and effective processing is taking place. At least, I can't think of any other explanation. But this is still strange, how is it possible that Canon come up with such an algorithm but nobody else? I don't think they are averaging pixels or doing post processing on the raw data. That would show in the spatial resolution, and it would be especially bad on stars. Nikon's median filter shows such effects, for example. Roger |
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Sensor noise: Nikon D200 versus Canon S70
"Bart van der Wolf" writes:
"acl" wrote in message ... .... Any idea how this can happen (except by some very effective image processing before doing anything else to the raw data)? There may be some specific noise suppression in the DIGIC processor as well, but at least it is not obvious (apart from the absence of noise). Most of it is in the much inproved photo-diode resetting in CMOS units, and using double correlation read-outs. -- Paul Repacholi 1 Crescent Rd., +61 (08) 9257-1001 Kalamunda. West Australia 6076 comp.os.vms,- The Older, Grumpier Slashdot Raw, Cooked or Well-done, it's all half baked. EPIC, The Architecture of the future, always has been, always will be. |
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Sensor noise: Nikon D200 versus Canon S70
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