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Author Topic: Low Canon DxO dynamic range versus Sony/Nikon  (Read 16113 times)

Kirk Gittings

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Re: Low Canon DxO dynamic range versus Sony/Nikon
« Reply #20 on: February 05, 2012, 10:49:47 pm »

Quote
for stills moire can be removed easily in PS

Sometimes yes, many times no-a total PITA.
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Kirk Gittings

marcmccalmont

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Re: Low Canon DxO dynamic range versus Sony/Nikon
« Reply #21 on: February 06, 2012, 12:10:39 am »

Marc
you mention canon lenses and the pentax K5.  Do you use the K5 for landscape work and a canon body for other work?  Just curious as I weigh my options.

Thanks,
Kyle

My main camera was a 5D then the 5DII but I purchased a K5 as a travel camera and found the sensor so good (DR) that it makes me want the same DR in my Canon. Once you get used to the clean shadows the 5DII shadow noise starts to bother you. I have so many Canon lenses that I cant switch to Nikon or Sony for the superior sensors. My Phase One P30 was much better than the 5D in the shadows (DR) and then the P45+ was a bit better, then my K5 was a nother noticeable improvement and now my IQ180 is on par with the K5 as far as noise. Problem with the Pentax is the lack of really good lenses. If you don't have a lot of lenses Nikon is your best bet now. Lets see how this next generation of Canons come out, I was disappointed on the DxO results of the Canon Gx1 as I was hoping for better DR with it being a newer sensor than the 7D. I was really hoping for a big improvement with the 5DIII but Erik pointed out it's the Sony onboard ADC's so I'm not holding my breath.
Marc

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Marc McCalmont

ejmartin

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Re: Low Canon DxO dynamic range versus Sony/Nikon
« Reply #22 on: February 07, 2012, 12:22:15 am »

Hi Bill,

Are you sure?

It seems to improve dynamic range (engineering definition) by about 1 stop, since the standard deviation is roughly halved.
I don't know if/how DxO accounts for that.

Cheers,
Bart

As I recall, DxO extrapolates read noise from measurements of SNR comfortably above clipping.  The test protocol is probably somewhere on their site.  I know the SNR curves they present are mathematically generated from a three-parameter fit of the actual data to read noise, shot noise, and PRNU, from measurements at a variety of brightness levels.
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bclaff

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Re: Low Canon DxO dynamic range versus Sony/Nikon
« Reply #23 on: February 07, 2012, 12:40:07 am »

As I recall, DxO extrapolates read noise from measurements of SNR comfortably above clipping.  The test protocol is probably somewhere on their site.
I'm not aware of that.
I know the SNR curves they present are mathematically generated from a three-parameter fit of the actual data to read noise, shot noise, and PRNU, from measurements at a variety of brightness levels.
Yes, I'm pretty sure they are generated.
Very poorly so since a quadratic fit will not yield sensible read noise, gain, and PRNU values.

As far as I know they take signal and noise readings at about 15 different brightnesses.
Beyond that, despite other appearances, I find what they do is not transparent but rather opaque.

Best regards,
Bill
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bjanes

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Re: Low Canon DxO dynamic range versus Sony/Nikon
« Reply #24 on: February 14, 2012, 06:56:42 pm »

Only some specialized programs expose the optical black data.

Bill,

I recently learned about a program to look at raw files, RawDigger (www.rawdigger.ru), presumably from Ilia Borg's colleagues in Russia. It looks to be very promising, and it does have an option to show "masked pixels", presumably the optical black area. With the D3, I see a row two pixels on the left and right extremes of the frame. Are these the optical black?

Regards,

Bill Janes
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bclaff

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Re: Low Canon DxO dynamic range versus Sony/Nikon
« Reply #25 on: February 14, 2012, 07:49:23 pm »

Bill,

Yeah, on the D3 there are two columns to the left of the effective area and two to the right.
I only really trust the two to the left.

Regards,
Bill
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bclaff

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Re: Low Canon DxO dynamic range versus Sony/Nikon
« Reply #27 on: February 15, 2012, 12:34:41 am »

My impression is that this is a program to correct for a "Tinge" error that occurs due to improper (or non-use?) use of the optical black data on Pentax K20D/Samsung GX20 cameras.
I don't think the optical black data exists primarily for use by raw converters (including in the camera) but I can certainly envision secondary uses.

Regards,
Bill
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torger

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Re: Low Canon DxO dynamic range versus Sony/Nikon
« Reply #28 on: February 15, 2012, 03:00:14 am »

Canon is good at lenses, and not so good at sensors. Unfortunately I don't think sensor performance will be at Sony Exmor level in the coming generation of Canon cameras. The typical user don't care about sensor quality differences, since the different manufacturers are close enough to each-other, so I don't think Canon is very pressed to be on top.

Sensor-wise for the landscape photographer Nikon D800 seems to be a safe bet. I'm heavily invested in Canon lenses and when it was 5Dmk2 vs D700 it was sure better to have the Canon resolution despite slightly less good DR, but 5Dmk3 is rumored to be 22 megapixels and if the trend continues the DR will probably be slightly worse than Nikon's (Sony's) D800 36 megapixel (especially considering pattern noise, an artifact that dxomark does not measure but greatly reduces the subjective "photographic DR"), so then you have a camera with less resolution and less DR, at least at ISO100.

If I would invest from scratch today, it would be a really tough choice. I prefer Canon for the lenses, but Nikon for the sensors (D7000, D3s, D3x, D800).

Based on loose rumors there is a chance that Canon will introduce two new bodies this year, the all-around 5Dmk3 (faster than D800, but less MP and probably a bit less DR at ISO100) and another "Cinema DSLR" which actually may be very high res in stills mode. DR will in any case be less good than Sony Exmor - Canon simply does not have the technology to compete - that is I don't think that they choose to prioritize other things, they simply can't do it at this time even if they wanted to. However, differences are not huge, it is more of an irritation when one sees the noise and knows that competing products are better rather than it is a practical problem in making images. In the cases I use HDR techniques I would need HDR also with a Sony Exmor sensor, I don't think my workflow would change with 1 extra stop of photographic DR. So for me personally I'm more worried about Canon possibly not being competitive with resolution than DR, as long as they don't move backwards on that.

Some of the Canon lenses seems to scream for higher resolution sensors though, and the new 24-70 they seem to prioritize high resolution ahead of image stabilization, so I would be surprised if Canon will not come up with a 30+ megapixel body sooner or later, but it may be in a costly pro package (will make 1DsIII pro users happy, but not cost-sensitive 5Dmk2 users), and maybe not this year.
« Last Edit: February 15, 2012, 03:36:05 am by torger »
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BJL

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Re: Low Canon DxO dynamic range versus Sony/Nikon
« Reply #29 on: February 15, 2012, 08:33:31 am »

Canon is good at lenses, and not so good at sensors.
It is surprising how quickly opinion has flipped on Canon's former DSLR sensor leadership, and it might confirm my long-time skepticism about the idea that doing it all in-house is inherently superior to striking a balance of doing what you do best in-house and then out-sourcing when that offers the advantages of size and shared resources. (At the risk of cliché, Apple is a prominent example of balancing the use of out-sourced and commodity components and technologies with creating product differentiation through in-house exclusives. And all the high-end computer makers who tried to stay with their own processors have been over-run by competitors that use Intel x86 and differentiate at a higher level in the product design stack.)

But I am optimistic that the recent advantage for Sony (and maybe also the Panasonic GH2 video-oriented sensor) comes largely from a single change in technology, which Canon could develop and deploy fairly soon: on-chip column-parallel AD conversion.
« Last Edit: February 15, 2012, 06:42:01 pm by BJL »
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deejjjaaaa

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Re: Low Canon DxO dynamic range versus Sony/Nikon
« Reply #30 on: February 15, 2012, 10:01:29 am »

My impression is that this is a program to correct for a "Tinge" error that occurs due to improper (or non-use?) use of the optical black data on Pentax K20D/Samsung GX20 cameras.

your point is that camera's firmware/image processing hardware should correct the raw data before a raw file is written by firmware ?... that certainly did not happen in Pentax's case w/ Samsung sensor, hence GordonBGood (nickname @ dpreview) wrote a program that corrected the raw data using the masked pixels to be used in a workflow before raw converters
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bclaff

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Re: Low Canon DxO dynamic range versus Sony/Nikon
« Reply #31 on: February 15, 2012, 10:25:53 am »

Quote
your point is that camera's firmware/image processing hardware should correct the raw data before a raw file is written by firmware ?.

No, but the program was necessitated by some raw converter (perhaps even the one in the camera that creates JPGs) not doing it "right"
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scooby70

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Re: Low Canon DxO dynamic range versus Sony/Nikon
« Reply #32 on: February 15, 2012, 10:37:15 am »

I am ready to upgrade my canon 5D body which I have used for 6 years. 

Whenever the subject of Canon v Nikon/Sony DR gets raised there is always some technical talk about the reasons for any differences and there is often the view that Canon aren't that bad and anyone who thinks that they should be avoiding the issue by using flash, stacking, HDR or some other technique. However, there are some absolutely stunning demonstrations of Nikon v Canon DR on the net and for me personally it's obvious, regardless of the reason, that Nikon simply blows Canon out of the water in this respect these days.

If buying into a system today Canon would not be my first choice unless I was willing to accept the weakness (as I see it) in DR order to get some other advantage like being able to use a specific lens which Nikon doesn't offer.
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deejjjaaaa

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Re: Low Canon DxO dynamic range versus Sony/Nikon
« Reply #33 on: February 15, 2012, 02:30:27 pm »

No, but the program was necessitated by some raw converter (perhaps even the one in the camera that creates JPGs) not doing it "right"

actually there were no raw converters that were doing it right - no commercial no free/opensourced and people tried a lot of them... and also that was a sour point w/ Adobe  DNG converter which was removing those masked to light sensors during the conversion and so made it impossible to fix the issue (since then, but may be not for that reason, Adobe reversed the approach and now they do not delete that data  8)) for converted .DNG files (in camera .DNG files were naturally OK).
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