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11-05-2010, 07:18 AM   #61
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So we went from megapixel race to DR/Noise race, which seems to be coming to a close. What next?

11-05-2010, 07:21 AM   #62
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QuoteOriginally posted by gazonk Quote
Haha
Maybe it was good for Pentax that it didn't beat the 645D in the overall ranking

(I still think that for some professionals, the 645D can do a lot of things the K-5 can't. Especially if you're printing very large)
The fact that it could 'beat' the 645D 'score' at all would be an interesting thing, and possibly a mild indictment of DxO. The Individual sensor attribute ratings are useful, but what does the overall 'score' actually measure?

I think someone compared it to the old synthetic "Winstone" scores for CPUs, which everyone eventually agreed didn't mean much.

(K-5 is now the aps-c high-ISO leader, though, which I think we all suspected!)

.
11-05-2010, 07:21 AM   #63
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Interesting Falk, what are your comments with regards to seeing the same advances applied to the full-frame market?
11-05-2010, 07:24 AM   #64
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QuoteOriginally posted by falconeye Quote
On the other hand, it only leaves maybe one more stop DR which is feasible with a sensor of that size, i.e., DR 15.0-15.5 is kind of a barrier for APSC sensors without offering native lower iso (an ideal sensor of the same full well capacity would have 15.7 EV DR).
I think it's pretty interesting that ISO 80 actually offers more DR than ISO 100.

I hope to be able to replace my K10D with the K-5 some time next year, and just the idea of having 2.5 EV more DR than I currently have at ISO 100 is almost incomprehensible. After all, I feel the K10D has a lot of RAW headroom at low ISO.

11-05-2010, 07:30 AM   #65
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QuoteOriginally posted by jsherman999 Quote
The Individual sensor attribute ratings are useful, but what does the overall 'score' actually measure?
I think it gives a reasonable measure of the camera's overall IQ if used in very diverse situations. So it's probably most useful for all-round amateurs, while the individual ratings make more sense for photographers specializing in one or more fields.
11-05-2010, 07:34 AM   #66
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DxOMarks makes me feel better after I spent €1100 for K-5 yesterday...
11-05-2010, 07:38 AM   #67
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QuoteOriginally posted by Big G Quote
what are your comments with regards to seeing the same advances applied to the full-frame market?
None except from trivial ones

QuoteOriginally posted by gazonk Quote
I think it gives a reasonable measure of the camera's overall IQ
DxO overall sensor score should never be consulted. A novice user should go to the usual test report which evaluates other camera aspects and brings everything in proportion, like dpreview does. The target audience of DxO is such that individual scores and only those, should always be consulted.

OTOH, it doesn't matter for the K-5. It simply scores best for APSC everywhere:

Best in dynamic range, best in low light, best in color sensitivity and second in resolution (beaten by the 7D).

OTOH and of course, it cannot compete with full frame for low light and resolution.
11-05-2010, 07:45 AM   #68
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QuoteOriginally posted by gazonk Quote
I think it gives a reasonable measure of the camera's overall IQ if used in very diverse situations. So it's probably most useful for all-round amateurs, while the individual ratings make more sense for photographers specializing in one or more fields.
Yes, but my question was more specific about what it actually measures, not what it (maybe) corresponds to. I don't think I've actually seen a breakdown of what goes into that number, not even a simplified criteria weighting. (unless I missed it.)

As Falk implies, the overall 'score' is not a real measure of anything, just a rating, almost subjective in it's obscurity! (that bad word, subjective)

(But it's simple, and it drives traffic to the site.)

11-05-2010, 08:13 AM   #69
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I love how it went from hating dxo to loving dxo. I cant wait for D800 and 5D mark iii. They are going to be crazy. In case some didnt see what i posted in a different thread, 5D is supposed to be 28 MP with 102k ISO. Should be one hell of a camera.
11-05-2010, 08:16 AM   #70
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DXO have reams and reams of material on the dxomark.com websitte that explains their methodology and what all the numbers mean. Eg:

DxOMark - Learn more
DxOMark - Sensor Scores
DxOMark - DxOMark testing protocols
and
DxOMark - Our publications

Their site is so rich in data now that it is, however, easy to get swamped by it all.
11-05-2010, 08:24 AM   #71
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QuoteOriginally posted by Raylon Quote
I love how it went from hating dxo to loving dxo. I cant wait for D800 and 5D mark iii. They are going to be crazy. In case some didnt see what i posted in a different thread, 5D is supposed to be 28 MP with 102k ISO. Should be one hell of a camera.
But the new Canon and Nikons are both going to be FF. Relatively speaking the D7000 result will be more interesting.

Not all of us are DXO flip-flops. Some of us have been DXO fans for quite a while. I used to get all sorts of flak about DXO myself here a while ago. Numbers and tech evaluations are always good and necessary when you are talking optics and electronics. But they can always be mis-interpreted.
11-05-2010, 08:38 AM   #72
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DxO is one of many variables that one should consider when looking at "which camera is right for me".
11-05-2010, 08:38 AM   #73
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QuoteOriginally posted by rawr Quote
But the new Canon and Nikons are both going to be FF. Relatively speaking the D7000 result will be more interesting.

Not all of us are DXO flip-flops. Some of us have been DXO fans for quite a while. I used to get all sorts of flak about DXO myself here a while ago. Numbers and tech evaluations are always good and necessary when you are talking optics and electronics. But they can always be mis-interpreted.
.

I like DxO, it provides a valuable touchstone for individual sensor attributes, but the 'overall score' is defined as:

QuoteQuote:
What does Sensor Overall Score show?

* Sensor Overall Score shows:
o the quality of the sensor in terms of noise.
o the ability to render high contrast.
o the formation of colored noise.
o the ability to shoot in low light.
* Sensor Overall Score does not show:
o the resolution of the camera, i.e., its ability to render fine details.
o the quality of the lens.
o the optical aberrations.

How is it measured?

The Sensor Overall Score is an average of the Portrait Score based on Color Depth, the Landscape Score based on Dynamic Range and the Sports Score based on Low-Light ISO.
If you look at the Portrait, Color, and Low-Light score descriptions, it doesn't really bring any insight into their formula to derive the ovrall score. (again, unless I miss that formula.) So, the overall score is useful as a better-than-average subjective measure, and can be a feather in the cap that increases sales, but isn't as useful in determining the worth of the camera to your needs as looking at the individual attributes would be.

Personally I find the 'sports low-light' attribute score interesting, because it describes a real-life shooting situation that meets a big chunk of my needs - the 'sport' of low-light kid/family shooting. Toddlers are slow-moving athletes, but they're often moving in even lower light than, say, a gym or soccer field.

Here's that attribute description:



QuoteQuote:
Sports & action photography: Low-Light ISO

Unlike the two previous scenarios in which light is either generous (studio) or stability is assured (landscape), photojournalists and action photographers often struggle with low available light and high motion, so that achieving usable image quality is often difficult when pushing ISO.

When shooting a moving scene such as a sports event, action photographers’ primary objective is to freeze the motion, giving priority to short exposure time. To compensate for the lack of exposure, they have to increase the ISO setting, which means the SNR will decrease. How far can they go while keeping decent quality? Our metric, Low-Light ISO, will tell them.

The SNR indicates how much noise is present in an image compared to the actual information (signal). The higher the SNR value, the better the image looks, because details aren't drowned by noise. SNR strength is given in dB, which is a logarithmic scale: an increase of 6 dB corresponds to doubling the SNR, which equates to half the noise for the same signal.

An SNR value of 30dB reflects an excellent image quality. Low-Light ISO is then the highest ISO setting for the camera such that the SNR reaches this 30dB value while keeping a good dynamic range of 9 EVs and a color depth of 18bits.

As cameras improve, the Low-Light ISO will continuously increase, making this scale open.

A difference of Low-Light ISO of 25% represents 1/3 EV and is slightly noticeable.
11-05-2010, 08:44 AM   #74
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QuoteOriginally posted by opiedog Quote
what surprises me is some folks reaction to the kr DXO numbers.

yes, we all expect it to be better than the kx, but some reaction like "don't believe DXO, it's garbage"

now, with the K5, "all right! DXO numbers for k5 are great!" excellent.

well, as someone else mentioned, it's human nature.
HAHA,

I trust my lyin' eyes!

Well... to be fair, I accepted the K-r demise.
And though, I do realize it sits rightfully with respect to the competition, I would have liked Pentax to push for better than average to keep thing on the up and up.

But... since the K-x was the product of confusion last year.
I guess its only fair that they leave the K-r where the K-x left off given it was above average too(nothing wrong with that I guess).

Great to see the best in class this year is a Pentax!
And the first ever APS-C to tread FF territory is a Pentax!
Yay Pentax!
11-05-2010, 08:52 AM   #75
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I don't think everyone is negative on Dxo. I personally was completely unsurprised by the Kr score, just as I am completely shocked by the K5 DR and high scores. Sure, they aren't perfect, but they are independent and call things as they measure them, even if we don't like the results (K7 worse than the K20). Just because something is newer doesn't make it better, but in this case, it seems like it is.
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