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Old Nov 6, 2010, 7:49 AM   #11
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Harriet,
You of course raise a very valid point. The sensor performance is only one aspect of the decision process. Some people seem to want to jump to the conclusion that this means the K-5 is akin to Nikon's D3s - they're still different animals. And there are certainly other features unrelated to the sensor that a photographer may deem important. So I'm not quite ready to sell off my 1dIII and lenses to buy the K-5, but within the context of sensor performance I'm very impressed. Always like to see QUALITY improved, not just quantity (one of my pet peeves with Canon is they seem more obsessed with quantity over quality).
Gees looking at those numbers for the K-5 it makes my 7D look like a babies toy, now what? maybe time to sell the 7D and buy the K-5, but also will keep my 5D II and sell it once the 5D III is released.
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Old Nov 6, 2010, 8:01 AM   #12
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...we know the pentax is definately sony chip - pentax has openly said so at photokina but has nikon said that the d7000 is a sony chip?
We know sensor in the D3100 is not a Sony chip. But, the D7000 sensor has got Sony written all over it according to some sources (packaging, wiring, etc.). There may be some differences incorporating features Nikon wanted into a Nikon specific design. But, my guess is that it's basic sensor design (photosites, microlenses, etc.) as the one Sony and Pentax are using (and those may have some minor differences, too).

Sensor specs can be misleading, as different manufacturers tend to report specs in different ways, mask off different edge photosites leading to resolution differences, etc. So, there's no way to tell for sure what differences exist unless you happen to be a Nikon or Sony engineer involved in that area. lol

Sensor ratings can also be misleading. For example, Nikon has been known to "pre-process" the raw data with some of their models, which can skew the results.

Pentax does the same thing. They just aren't as subtle about it as Nikon. So, DxOMark tests show a different graph legend once raw level noise reduction kicks in with Pentax dSLR models (showing where the results are smoothed by processing of the raw data by Pentax cameras, since they did it in a way that DxOMark detected and tries to account for by changing the graph legend when that happens)

IOW, they can be useful in some areas. But, I wouldn't put a lot of faith in those tests, as S/N ratio tests don't usually take actual retained detail into consideration (due to NR at the raw level, AA filter differences and more, which can skew some of the results).

Also, you have to keep sensor response curves in mind and what it takes to produce usable images, as you'd probably have very flat looking photos trying to squeeze as much DR into an image as the raw tests show.

In addition, those types of tests don't take lighting temperature differences into consideration (and you can see different sensor response curves with different lighting temperatures, with some cameras doing better than others in tungsten lighting, where you're more likely to use higher ISO speeds, with most of the tests you see using simulated daylight lighting instead).
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Old Nov 6, 2010, 8:57 AM   #13
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... I wouldn't put a lot of faith in those tests, as S/N ratio tests don't usually take actual retained detail into consideration (due to NR at the raw level, AA filter differences and more, which can skew some of the results).
For example, there is evidence to suggest that Nikon applies a type of long exposure NR to raw files with some models (and it can't be turned off by camera settings).

http://www.astrosurf.com/buil/nikon_test/test.htm

There is also evidence to suggest that Nikon applies a type of NR processing to raw files from some models like the D90, regardless of camera settings. Here's a discussion about it, using Rawnalyze to look at the raw data prior to the demosaic process:

http://forums.dpreview.com/forums/re...ssage=32401883

You'll also notice some reviewers mentioning that the D90 falls short of the D300 image quality using both raw and jpeg. Yet, the D90 tests better looking at DxOMark sensor rankings, and there is some evidence that suggests it's using NR at the raw level. That can skew test results, as the camera with better detail at the pixel level is not necessarily the one that tests better on S/N ratio tests. ;-)

Dave Coffin (the author of dcraw.c ) noticed that Nikon was pre-processing raw data years ago (applying multipliers at the raw level). See question #12 from this interview with Dave in 2005:

http://www.dpreview.com/news/0504/05...ninterview.asp

Some cameras need more correction in different lighting temperatures, too. The way a camera (or a raw converter) applies white balance settings is via RGB multipliers. So, if you need to "push" (increase the values) for a given channel (Red, Green or Blue) more in one camera versus another to correct for lighting, that can impact noise levels and DR.
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Old Nov 6, 2010, 10:10 AM   #14
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John the K5 is rubbish .... now you owe me. Can I get a loan for a K5 now?
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Old Nov 6, 2010, 12:38 PM   #15
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As a jpeg shooter...
JPEG or RAW... the source is the sensor. The better the sensor and the electronics behind the better your image data CAN be. This is without postprocessing in mind (and in-camera JPEG generation IS conversion already, not to mention the other postprocessing that is done)

For example - you'll profit from a high dynamic range in your JPEG's, too. And that's nothing to put down, right? Lesser noise in high ISO shots is another example.

Just my 2 cents,
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Old Nov 6, 2010, 1:13 PM   #16
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John the K5 is rubbish .... now you owe me. Can I get a loan for a K5 now?

thanks for that feel much better about things now - and yeah i do owe you but it will have to be a like for like exchange and next time you need talking out of a product let me know and i'll tell you how useless it is
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Old Nov 6, 2010, 1:21 PM   #17
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I'm just stunned, I had high hopes, but this is ...

I only hope they haven't made a typo.
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Old Nov 6, 2010, 10:40 PM   #18
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I was very impressed with that test and how both the K5 and the Pentax 645 D performed. I'd love to get a K5 and I win the lottery I would get the 645 D.
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Old Nov 8, 2010, 9:37 AM   #19
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Nikon D7000 results are in. As expected, very similar to the Pentax (with very slight edge to Pentax at higher ISOs). Of course the fanboys from both camps will debate endlessly but sensor performance from both seems to be so close as to be a non-factor in RAW. Not sure how the jpeg engines from both will shake out.
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Old Nov 8, 2010, 11:13 AM   #20
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anyone feeling sorry for canon aps-c shooters hehe =) ahhhhh cant laugh k7 does not score well but yeah results are pretty close so would appear that they are the same sensor and differences are in the processing
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