Most of what I've read suggests that Canon's high-ISO prowess is due to CMOS sensor technology, but I was curious if any of it was due to software algorithms used to process that data?
In an extreme difference example, Canon's NR technology doesn't result in super-smudgy images whereas other manufacturers suffer from their aggressive or different application of NR. That or with NR turned down there's tons of sensor noise.
I don't think Canon has much of a lead in sensor noise any more. They used to, but with the advent of the Nikon D3 and D700, Canon is a bit behind Nikon in the noise department. In APS-C cameras, it looks like Canon may still have a bit of the lead judging by raw captures. Nikon still uses too much NR to achieve their clean looking jpegs.
Sony's new backlit sensor looks like it could be a very big step forward. And then there's Kodak's new tech for low light with a alternate Bayer pattern. I wonder how that's progressing?
Interesting in scientific applications CCD is still king. I know of a camera that can shoot 100 million fps for watching the evolution of microbubbles and the sensor is a CCD with a native ISO of 100000 (at room temperature) and the noise is very good.
Supposedly CCDs have better noise control than CMOS so I'm not sure exactly what changes and optimizations Canon did with their sensors to lower the noise so much. It took Nikon a while to catch up with their CCD sensors to Canon's CMOS.
The modern CMOS technology uses circuitry to reduce noise by draining electric charge from each pixel before capturing an image but the modern cameras also use in-camera post-capture processing. Much of the improvement in recent cameras is due to improved in-camera processing rather than improved CMOS technology. That is why the results are not overwhelmingly better than for the previous generation cameras once you apply an external noise reduction program to the images, and why there was no great leap in usefl (clean) dynamic range. The hardware that does the best seems to be the hardware with the latest CMOS technology PLUS large pixels. There's no smudging caused by that combination but there can be some caused by the in-camera data processing, especially at extreme ISOs.
Nikon's CCD sensors never did catch up with Canon's CMOS sensors. They only jumped ahead when they introduced the large-pixel CMOS sensor in their D3. Having an AF system that worked was an added bonus.
Ariel Bravy wrote:
Supposedly CCDs have better noise control than CMOS so I'm not sure exactly what changes and optimizations Canon did with their sensors to lower the noise so much. It took Nikon a while to catch up with their CCD sensors to Canon's CMOS.
They didn't, there are no CCD chips even close to the CMOS chips now in the new Nikon cameras.
alfarmer wrote:
Most of what I've read suggests that Canon's high-ISO prowess is due to CMOS sensor technology, but I was curious if any of it was due to software algorithms used to process that data?
In an extreme difference example, Canon's NR technology doesn't result in super-smudgy images whereas other manufacturers suffer from their aggressive or different application of NR. That or with NR turned down there's tons of sensor noise.
Just curious...
ALF
My vastly amateur, uneducated and non-technical guess is you can do hardware NR on CMOS, while you can't do that on CCD (hence the software NR and the impressionist pictures we've seen from Nikons). Anyway this is what I've read in a magazine some years ago, I don't trust the magazine in the first place so it might be wrong . It also helps that Canon makes their own sensors, so apparently they have a pretty good idea how every single part of it works, while most other manufacturers were shopping for sensors at Sony (how many cameras used their 6mpix sensor? A lot).
What prompted the question was my recent purchase of an Olympus E420 and what is arguably their best lens (the 50mm f/2 macro). In just over a month with the camera, I've found two things on my 5D that have forever spoiled me -- high ISO performance and AF intelligence/accuracy.
For whatever reason, ISO 800 on the E420 is noisy and ISO 1600 can border on completely unacceptable in darker situations. Thank goodness for Noise Ninja! I was just wondering if Canon has some software algorithm patented, which allows them to have cleaner images that aren't "smudged" by NR.
The more-difficult thing to get used to coming from the 5D to the E420 is AF. I don't understand "EV" numbers but apparently the E420 can only focus down to EV-0 while the Canons can focus at EV-2. Oddly enough, that's a HUGE thing. A much bigger deal than I'd have suspected, so luckily my E420 is for vacation where there's typically plenty of light.
While on the subject of AF -- does Canon do it differently than Olympus or is their sensor node just bigger? I just notice the sensore "square" in the viewfinder is MUCH bigger on my 5D when it blinks/focuses than the one on the E420.
LMCasey wrote:
I don't think Canon has much of a lead in sensor noise any more. They used to, but with the advent of the Nikon D3 and D700, Canon is a bit behind Nikon in the noise department.
ALF, Canon info about the size of the AF sensors is a bit difficult to find. Info about how many main-sensor image pixels corespond to each AF-sensor pixel is impossible to find because Canon won't release it.
Small cameras use small sensors with small pixels which have a relatively poor signal to noise ratio regardless of the level of sensor and processing technology being used. e.g. as evidence of this the Canon G9 is quite noisy at ISO 400 even though it is a recent model and supposedly has the same Digic III computer as in the up-market DSLRs.
Brainiac, I won't even try to guess which image came out of which camera, but an even harder test would be to correctly apply Neat Image Pro to each one and then try to tell them apart.
Ariel Bravy wrote:
Supposedly CCDs have better noise control than CMOS so I'm not sure exactly what changes and optimizations Canon did with their sensors to lower the noise so much. It took Nikon a while to catch up with their CCD sensors to Canon's CMOS.
CMOS has readout electronics at each photosite while CCDs do not. Placing electronics at each photosite introduces pattern noise and reduces real estate for the photosite. Canon has technology that eliminates the pattern noise. Having the readout electronics closer to the site reduces noise while on the other hand so does a larger photosite.
HEI,you,people,did you saw what"JPEG"s are making NIKON Dslr-sDAMN,are so ,so soft;mostly I'm taking weddings pictures and I only shoot JPEGs(I don't need to shoot RAW because after so many years I think I'm very good on controling exposure)and for me THE CANON DSLRs are the best because are delivering the best JPEGs in the world,I SAW Jpegs made by NIKON D300, D3 and I think the D700 IT will be the same:AWFUL Jpegs, extremely soft,and very unnatural(because of very strong NR aplied in the camera)I THINK ,CANON is still the best on quality image department,IT'S MORE IMPORTANT TO DELIVER A SENSOR THAT PRODUSE A VERY LITTLE NOISE THAT TO ELIMINATE NOISE IN CAMERA(like NIKON DOES)
"Most of what I've read suggests that Canon's high-ISO prowess is due to CMOS sensor technology, but I was curious if any of it was due to software algorithms used to process that data?"
> 5D, D3, D700? The last two look nearly identical, so that's my bet.
The cameras are... 1Ds3, 1Ds3, D3. Sic.
My point is that Canon's best kept high iso secret is that the 1Ds3 is better than the D3 at high iso's.
Now I expect a deluge of people saying 'rubbish! look at this online comparison, and that, and that'. Please don't bother unless the comparisons show the D3 ouput uprezzed to 21 megapixel. Comparing 100% crops at different magnifications, as done on almost all test sites, is thoroughly misleading. It is like showing a square inch cut out from an A4 print, and another square inch cut out of an A3 print. The A4 cut-out looks less noisy, even if the camera isn't as good.
When comparing 100% crops from a 12 Mpixel and 21 Mpixel camera, the 21 Mpixel file is equivalent to a much bigger print. A fair comparison on a perfect monitor would be to examine the noise in the 12 megapixel file at 175%. It's bigger and worse than it seemed at 100%.
The crops above are from no less trusted a source than Phil Askey's DPReview. He plainly states that the D3 is better at iso's above 1600, because he failed to uprez the D3 file to 21 Mpixels, and so misjudged his own crops.
DAMN,are so ,so soft;mostly I'm taking weddings pictures and I only shoot JPEGs(I don't need to shoot RAW because after so many years I think I'm very good on controling exposure)and for me THE CANON DSLRs are the best because are delivering the best JPEGs in the world,I SAW Jpegs made by NIKON D300, D3 and I think the D700 IT will be the same:AWFUL Jpegs, extremely soft,and very unnatural(because of very strong NR aplied in the camera)I THINK ,CANON is still the best on quality image department,IT'S MORE IMPORTANT TO DELIVER A SENSOR THAT PRODUSE A VERY LITTLE NOISE THAT TO ELIMINATE NOISE IN CAMERA(like NIKON DOES)