Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
03-09-2010, 08:37 AM   #1
Senior Member




Join Date: Jan 2010
Location: British Columbia
Posts: 120
Pentax Kx Now on dxoMark

Check it out:

Kx

03-09-2010, 08:53 AM   #2
Veteran Member
theperception2008's Avatar

Join Date: Aug 2009
Location: Łódź, Poland and Riverside, California, U.S.A
Photos: Gallery | Albums
Posts: 488
QuoteOriginally posted by taurus9 Quote
Check it out:

Kx
Man the K-x's sensor is just an amazing sensor, I just browsed through and compared the K-x to the K20d and the K-7. It's just a better sensor...

So now who makes the sensor for the K-x again? I don't think Samsung did...
03-09-2010, 09:04 AM   #3
Veteran Member




Join Date: Jun 2009
Location: on the wall
Photos: Gallery
Posts: 715
I can't really parse their data, but the K-x scored relatively well amongst other DSLRs.
03-09-2010, 09:15 AM   #4
Veteran Member
falconeye's Avatar

Join Date: Jan 2008
Location: Munich, Alps, Germany
Photos: Gallery
Posts: 6,863
Almost exactly what I published in my blog months ago.

Nikon D5000 and Pentax K-x are the same up to measurement errors and the raw file noise reduction in Pentax at ISO 3200 and higher.

ISO 100 0dB point in Full SNR is 0.021% (K-x) vs. 0.022% (D5000). 0.021% is 12.2EV or 12.5 EV in 8 MP print normalization.

This makes D90/D5000/K-x (Sony Exmor CMOS) the highest dynamic range cameras in APS-C and Nikon D3x and some MF cameras are the only ones beating it.

I find it strange that Sony itself never released an own camera with this sensor, e.g. as Sony Alpha 500...

Actually, if you look at the SNR curves for K-x and Alpha 500, it actually may (almost) be the same sensor, except that Pentax somehow managed to to get a lower ISO setting and reduced black noise.


Last edited by falconeye; 03-09-2010 at 09:24 AM.
03-09-2010, 12:28 PM   #5
Pentaxian




Join Date: Apr 2007
Location: Sweden
Posts: 1,951
So the d90 is still the low light (aps-c) king, and it has been out since 2008. That is even more impressive. Does the k-x use the same sensor?
03-09-2010, 03:09 PM   #6
Pentaxian




Join Date: Jun 2009
Location: GMT +10
Photos: Albums
Posts: 10,893
A creditable result for the K-x.

Pity it couldn't bump the D90 off it's low-light ISO crown, but the K-x did as well as the D90 on color depth and dynamic range. However I expected a higher lowlight-ISO score for the K-x. Even the Canon 7D beats the K-x (marginally) on low-light ISO, which I think is highly improbable, given the 7D's crowded sensor.

IMHO Pentax do need to do something about the RAW NR issues DXO have always identified when examining Pentax DSLRs, ie this stuff about the hard-coded compulsory NR [or NR 'cheating'] going on in the Pentax imaging engine RAW output:

QuoteQuote:
Noise filtering processing is present on the Pentax K10D (ISO 800 and ISO 1600), the Pentax K20D (ISO 3200 and ISO 6400), the Pentax K200D (ISO 800 and ISO 3200), the Pentax K7 (ISO 3200 and ISO6400) and the Pentax Kx (ISO 3200, ISO 6400 and ISO 12800).
DxOMark review for Pentax cameras

I suspect that issue considerably depresses the DXOMark low-light ISO scores for all Pentax DSLRs, particularly the K-x.
03-09-2010, 03:32 PM   #7
Veteran Member




Join Date: Jul 2009
Location: kobe/japan
Posts: 510
QuoteOriginally posted by falconeye Quote
Almost exactly what I published in my blog months ago.

Nikon D5000 and Pentax K-x are the same up to measurement errors and the raw file noise reduction in Pentax at ISO 3200 and higher.

ISO 100 0dB point in Full SNR is 0.021% (K-x) vs. 0.022% (D5000). 0.021% is 12.2EV or 12.5 EV in 8 MP print normalization.

This makes D90/D5000/K-x (Sony Exmor CMOS) the highest dynamic range cameras in APS-C and Nikon D3x and some MF cameras are the only ones beating it.

I find it strange that Sony itself never released an own camera with this sensor, e.g. as Sony Alpha 500...

Actually, if you look at the SNR curves for K-x and Alpha 500, it actually may (almost) be the same sensor, except that Pentax somehow managed to to get a lower ISO setting and reduced black noise.
yes, your test were very good. But it seem people need to see big names to believe it. First you were the one to comment about dynamic range. Then dpr and then now dxmark.
kx been very good for pentax.

-------------
for the post in other thread


overall comparison against k7




dynamic range



SNR




as expected dxomark also agrees that kx has better sensor overall. At high isos has better noise control at low iso better dynamic range.
03-09-2010, 05:11 PM   #8
Veteran Member
falconeye's Avatar

Join Date: Jan 2008
Location: Munich, Alps, Germany
Photos: Gallery
Posts: 6,863
QuoteOriginally posted by Gimbal Quote
So the d90 is still the low light (aps-c) king, and it has been out since 2008. That is even more impressive. Does the k-x use the same sensor?
AFAIK, yes.
Supposedly, the D90 plays some more raw NR tricks than D5000 or K-x, though.
The differences between the three cameras aren't significant. They perform the same. Differences showcase the instability of the DxO "low light ISO" score.
QuoteOriginally posted by rawr Quote
Even the Canon 7D beats the K-x (marginally) on low-light ISO, which I think is highly improbable, given the 7D's crowded sensor.
Sensors with a higher pixel density don't have better or worse noise perfomance. in the first place. This is a myth which seems to be very hard to defeat.
QuoteOriginally posted by rawr Quote
IMHO Pentax do need to do something about the RAW NR issues DXO have always identified when examining Pentax DSLRs, ie this stuff about the hard-coded compulsory NR [or NR 'cheating'] going on in the Pentax imaging engine RAW output:
[...]
I suspect that issue considerably depresses the DXOMark low-light ISO scores for all Pentax DSLRs, particularly the K-x.
Pentax has clearly superior low light score at high ISO before DxO applies their correction for ISO3200 NR. The inaccuracy of correction combined with instability of the low light ISO score renders this particular score somewhat random.
QuoteOriginally posted by zxaar Quote
overall comparison against k7
In this post, the comparison charts have not been scaled for equal resolution (one must click onto "print" in the upper left corner). The comparisons w/o the "print" normalization are raw data not appropriate for comparison.

In the form as presented, the charts are misleading. I propose to update the post and possibly, to include K20D as well (you'll be surprised ).

03-09-2010, 07:19 PM   #9
Veteran Member




Join Date: Jul 2009
Location: kobe/japan
Posts: 510
QuoteOriginally posted by falconeye Quote
In this post, the comparison charts have not been scaled for equal resolution (one must click onto "print" in the upper left corner). The comparisons w/o the "print" normalization are raw data not appropriate for comparison.

In the form as presented, the charts are misleading. I propose to update the post and possibly, to include K20D as well (you'll be surprised ).
i look at them as i get time in evening. (at the moment in office).
good idea to include k20d also. But somehow i feel k20d and k7 are very close.
03-10-2010, 01:17 AM   #10
Pentaxian
thibs's Avatar

Join Date: Jun 2007
Location: Belgium
Photos: Albums
Posts: 5,292
Falk, I'd rephrase your thorough analysis (well how I do understand things) and conclude that: once again, DXO mark is proven to be unreliable.

First their measures/methodology are flawed and second, the idea of resuming a sensor performances with a single indice is completely stupid and misleading, as any other single indice.

Why is there still people taking those scores into account but flame them is beyond me.
03-10-2010, 01:36 AM   #11
Pentaxian




Join Date: Apr 2007
Location: Sweden
Posts: 1,951
QuoteOriginally posted by thibs Quote
Falk, I'd rephrase your thorough analysis (well how I do understand things) and conclude that: once again, DXO mark is proven to be unreliable.
I don't think so, if read correctly I believe this is the best source on the net for comparing different cameras output. But one should (as Falk said) select the "print" option before comparing cameras with different resolution. It seems to me that most people who are bashing the results just doesn't know how to use the charts.

Anyhow, this sensor already has some years under it's belt, isn't it time for a new one to surface? Perhaps in a new d90 and, if we are lucky in the next k7 as well. Or perhaps Pentax aren't allowed to use the Sony sensors while they are new?
03-10-2010, 01:37 AM   #12
Pentaxian




Join Date: Apr 2007
Location: Sweden
Posts: 1,951
QuoteOriginally posted by thibs Quote
Falk, I'd rephrase your thorough analysis (well how I do understand things) and conclude that: once again, DXO mark is proven to be unreliable.
I don't think so, if read correctly I believe this is the best source on the net for comparing different cameras output. But one should (as Falk said) select the "print" option before comparing cameras with different resolution. It seems to me that most people who are bashing the results just doesn't know how to use the charts.

Anyhow, this sensor already has some years under it's belt, isn't it time for a new one to surface? Perhaps in a new d90 and, if we are lucky in the next k7 as well. Or perhaps Pentax aren't allowed to use the Sony sensors while they are new?
03-10-2010, 02:08 AM   #13
Veteran Member




Join Date: Jul 2009
Location: kobe/japan
Posts: 510
these are from print tab

k20d also included







make your conclusions. I am happy with my kx.

:-D
03-10-2010, 05:38 AM   #14
Veteran Member
falconeye's Avatar

Join Date: Jan 2008
Location: Munich, Alps, Germany
Photos: Gallery
Posts: 6,863
QuoteOriginally posted by zxaar Quote
these are from print tab
Thanks for the update.

Glad you included the K20D as you can see, K20D and K-x have the same low noise profile up to ISO 1600 (and K-7 not that much worse). It is DR where the K-x really shines.
03-10-2010, 06:58 AM   #15
Veteran Member
Laurentiu Cristofor's Avatar

Join Date: Nov 2009
Location: WA
Photos: Albums
Posts: 3,044
QuoteOriginally posted by taurus9 Quote
Check it out:

Kx
Finally, a Pentax camera that rates better overall than the K10D.
Reply

Bookmarks
  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
camera, dslr, kx, pentax kx, photography
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
DxOMark rates Pentax K-r lexurian Pentax News and Rumors 72 11-09-2010 04:05 PM
DXOMark evaluates the 645D rawr Pentax News and Rumors 30 11-08-2010 02:59 PM
DxOMark scores Pentax 645D det1rac Pentax Medium Format 1 10-26-2010 07:12 PM
(dxomark) K20D and K7. Reportage Pentax DSLR Discussion 20 01-13-2010 05:06 AM
DxOMark Sensor ranks yakiniku Photographic Technique 7 01-16-2009 11:01 PM



All times are GMT -7. The time now is 01:39 AM. | See also: NikonForums.com, CanonForums.com part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top