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12-11-2009, 05:26 PM   #16
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You guys don't be too guillable now, pictures have proven that the K-7 is just trailing the K20D in high ISO, yet this chart shows significant differences otherwise. They share the same sensor and the one in the K-7 is tweaked to be better although some claims show the K20D has a very slight upper hand in high ISO. Therefore this chart has something fishy about it, because seeing is believing and this data has no solid back-up to claim it's credibility. Now enough of that pixel peeping and crying stuff just because some website is throwing out unknown data as if it were fact, go out there and enjoy taking pictures so you can look at them knowing you're happy because it's just all BS.


Last edited by LeDave; 12-11-2009 at 05:35 PM.
12-11-2009, 05:34 PM   #17
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DXOmark scores are academically interesting but ultimately irrelevant. As several others have observed, the K-m scores at the bottom of the list while sharing the same sensor as the K200D. The E-510 sits well above the E-410 despite the fact that they're same-generation products with EVERY aspect of sensor circuitry and processing identical.

DXOmark scores simply do not reflect real-world performance. Don't go basing your opinions and decisions on these.
12-11-2009, 06:06 PM   #18
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What a waste of time.

No sense in quibbling over the difference between "Really good" and "Really really good"
12-11-2009, 06:15 PM   #19
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QuoteOriginally posted by LeDave Quote
They share the same sensor and the one in the K-7 is tweaked to be better although some claims show the K20D has a very slight upper hand in high ISO.
Having owned both I can say that this is not entirely accurate. I for one believe that the biggest misconception with noise, is found in the exponential nature of noise to begin with. That is to say, that though noise attributes(patterns) do not come-up as significant in the lower sensitivities, they often can or do present major performance differences down the line.

Such observations can be seen as the K-7 produces phenomenal image detail against other models, only to exhibit IQ degradation earlier than it's predecessor in the end(beyond ISO800).

I found the K-7 to be above average up to about ISO1600, after which, noise would began overcoming detail. By ISO3200, the K-7 proved to have to much noise to handle effectively and required both sizing and NR compromises. By ISO6400, shadow noise and blotching is very prevelant, and usually impossible to contain without serious intervention(ie. black & whites).

The K20D on the other hand, puts out manageable noise all the way to ISO6400. Which is hardly perfect by any means(like a Kx), but it can be coaxed into very good full page prints at these sensitivities.

Another often overlooked limitation brought-out by noisy sensors, is in post processing(shadow and highlights). Here, again... I've found the K-7 to present noise artifacts much sooner than the K20D. Though I wouldn't present this as a primary limitation, I think it's worth mentioning nonetheless.

We commonly shoot K20's at ISO3200 - 4000 with reliable results, whereas the K-7 couldn't provide us with the same workable output at such sensitivities.

I have nothing against the K-7 and a whole, in fact, we really wanted to upgrade our kits to them. However, after some trials and testing, we decided to skip the K-7 this round and wait for Pentax's next prosumer body.

I think the K-x sensor(as it were) is a very good indicator that Pentax rushed the K-7 for some reason or another. I also think that Pentax need to make an updated K-7x or similar to put the K-7 where it belongs in the marketplace.

12-11-2009, 07:36 PM   #20
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I get fine results out of my K-7, and I'm certainly not going to sell it because some chart says it's slightly worse than the K-7 in terms of statistics. It's a great tool.
12-11-2009, 07:59 PM   #21
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QuoteOriginally posted by kickboxingpenguin Quote
im embarassed... after months of researching the k-7 saying to myself "eh iso isnt that bad, look at all these features to distract you from that"... i might have to return my camera and go to canon =(
Orrrrrr, you could go and take pictures.

The actual results aren't "not bad" -- they can be downright excellent. These charts do a disservice because it looks like they go from bad to good, when really they go from "very very good" to "excellent".
12-11-2009, 08:38 PM   #22
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QuoteOriginally posted by Miserere Quote
There is no reason the K-7 should be worse than the K200D at high ISO.
It's the result of "naked" sensor.
Even top-managers of Hoya (in interview) said that Samsung sensor is not as good as they expected.

GordonBGood and oleg_v said the same at dpreview forum. K-7's sensor is rather noisy at low ISO and has the worst DR among Pentax DSLR.
Lets face the truth and make photos.
12-11-2009, 08:40 PM   #23
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QuoteOriginally posted by mithrandir Quote
Except for the low light category, the K10D continues to kick butt.
Too bad mine's had such a hard life in my hands (or more appropriately, when dropped from them) it won't AF for sh*t anymore...

12-11-2009, 09:26 PM   #24
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DXO and the Pentax K7 [Page 1]: Pentax SLR Talk Forum: Digital Photography Review
Attached Images
 

Last edited by ogl; 12-12-2009 at 02:58 AM.
12-12-2009, 03:40 AM   #25
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I am a bit disapointed by the A500 ISO score here.

Isn't it supposed to use the same sensor as the K-x?
12-12-2009, 03:48 AM   #26
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QuoteOriginally posted by lol101 Quote
I am a bit disapointed by the A500 ISO score here.

Isn't it supposed to use the same sensor as the K-x?
it seems to me - No.
12-12-2009, 04:38 AM   #27
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QuoteOriginally posted by lol101 Quote
I am a bit disapointed by the A500 ISO score here.

Isn't it supposed to use the same sensor as the K-x?
The A500's score is pretty respectable. Not quite D90, but very OK.

I think the A500 may have the same Sony sensor as the K-x, or at least one very close to it. However there are some clear differences between the cameras - eg the K-x does video and the A500 does not - that suggest that the sensors may not be identical.

But even if the sensors were 100% identical, each camera would have very different supporting circuitry (eg the imaging engine) and software (eg the firmware) developed independently by Sony and Pentax. These elements - which process the sensor's output - would also make a difference to a camera's DXOMark score.

So even though they may share the same sensor, the A500's score may not be a great guide to, for example, the potential DXO low-light ISO score of the K-x. Hopefully the K-x will be better.
12-12-2009, 05:12 AM   #28
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QuoteOriginally posted by JohnBee Quote
The latest K-7 scores bellow the K200D?
No.

When comparing sensors with different number of pixels, it is essential to click onto the PRINT button in the upper left corner of the chart. As otherwise, the comparison is meaningless!

When doing right, the K-7 is close enough to the rest of the pack.

QuoteOriginally posted by LeDave Quote
You guys don't be too guillable now, pictures have proven that the K-7 is just trailing the K20D in high ISO, yet this chart shows significant differences otherwise.
No, look at the charts. K-7 and K20D are almost the same. Maybe 1dB advantage for the K-20D in 18% Gray noise and almost same Dynamic Range up to ISO 800. The K20D has an advantage in DR for ISO of 1600 and higher (by ~0.8EV). The DR advantage at ISO 100 is suspicious as it disappears at ISO 200.


QuoteOriginally posted by er1kksen Quote
DXOmark scores are academically interesting but ultimately irrelevant. As several others have observed, the K-m scores at the bottom of the list while sharing the same sensor as the K200D.
This isn't exactly true.

Don't look at the DxOMark. It is bullshit. BUT! Look at the individual graphs which, when read correctly, are the best lab results being published to date. Esp. the Full SNR curves (not available in compare mode!).

You will see that DxO derives almost identical graphs (SNR 18%, Dynamic Range) for K10D, K200D and K-m.

These graphs are relevant.


The DxOMark score is bullshit for an obvious reason: it is independent of sensor resolution! A higher resolving sensor tends to score worse (*) while it should score better. Otherwise, a 4 pixel sensor will win every DxOMark competition

__
(*) DxO normalizes for resolution. But this is not enough when measuring DR. They would have to do their measurements on downscaled images which they can't because they use the mosaiced raw data.

QuoteOriginally posted by lol101 Quote
I am a bit disapointed by the A500 ISO score here.
Isn't it supposed to use the same sensor as the K-x?
As it seems, the A500 has a different sensor. I was surprised too. But DxO teaches us that the Sony OEM and Sony A500 sensors are distinct.


I have done own lab tests (in DxO style), for K-m (unpublished), K-x, K-7, Nikon D5000 and Nikon D700. They contain some additional detail which DxO missed, esp. for the D5000/K-x sensors which cannot be measured by an unaltered DxO measurement method. Their measures contain a flaw which I uncovered.

Read more about it in my thread and blog article:

https://www.pentaxforums.com/forums/pentax-news-rumors/83021-lumolabs-nikon-d...nge-noise.html
12-12-2009, 07:25 AM   #29
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QuoteOriginally posted by falconeye Quote
No.

When comparing sensors with different number of pixels, it is essential to click onto the PRINT button in the upper left corner of the chart. As otherwise, the comparison is meaningless!

When doing right, the K-7 is close enough to the rest of the pack.



No, look at the charts. K-7 and K20D are almost the same. Maybe 1dB advantage for the K-20D in 18% Gray noise and almost same Dynamic Range up to ISO 800. The K20D has an advantage in DR for ISO of 1600 and higher (by ~0.8EV). The DR advantage at ISO 100 is suspicious as it disappears at ISO 200.




This isn't exactly true.

Don't look at the DxOMark. It is bullshit. BUT! Look at the individual graphs which, when read correctly, are the best lab results being published to date. Esp. the Full SNR curves (not available in compare mode!).

You will see that DxO derives almost identical graphs (SNR 18%, Dynamic Range) for K10D, K200D and K-m.

These graphs are relevant.


The DxOMark score is bullshit for an obvious reason: it is independent of sensor resolution! A higher resolving sensor tends to score worse (*) while it should score better. Otherwise, a 4 pixel sensor will win every DxOMark competition

__
(*) DxO normalizes for resolution. But this is not enough when measuring DR. They would have to do their measurements on downscaled images which they can't because they use the mosaiced raw data.



As it seems, the A500 has a different sensor. I was surprised too. But DxO teaches us that the Sony OEM and Sony A500 sensors are distinct.


I have done own lab tests (in DxO style), for K-m (unpublished), K-x, K-7, Nikon D5000 and Nikon D700. They contain some additional detail which DxO missed, esp. for the D5000/K-x sensors which cannot be measured by an unaltered DxO measurement method. Their measures contain a flaw which I uncovered.

Read more about it in my thread and blog article:

https://www.pentaxforums.com/forums/pentax-news-rumors/83021-lumolabs-nikon-d...nge-noise.html


Ah, setting it straight like nobody else does. Awesome.
12-12-2009, 07:43 AM   #30
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I was reading a complaint thread in the Sony Forum at DPR about the lukewarm DPR review vs. the high DxO scores. The reviewer said something like "I was reviewing a camera, not a sensor". People should try to keep that thought in mind when looking at DxOMark.
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