Forgot Password
Pentax Camera Forums Home

Show Printable Version Search this Thread
12-15-2012, 07:23 PM   #1
Junior Member

Join Date: Jan 2010
Location: S.F. Bay Area
Posts: 30
K-x, K5, K30 noise

I was mulling through my old pop photo reviews (I know, I know.....) and it's interesting that the newer generation K-5(1st version) and K30 have inferior noise numbers than does the k-x at higher isos.

It's plausible to me that for a given generation of sensor that a 12MP with its bigger pixels could have better noise performance than a 16MP sensor BUT in this case, they are not of the same generation so you would expect improvement.

Here's what the reviews say:

iso 200 400 800 1.6k 3.2k 6.4k
k-x 1.5 2.3 2.6 2.9 3.2 4.1
k30 1.3 1.6 2.5 3.9 4.4 6.8
k5 1.5 1.9 2.2 2.7 3.4 5.1

I don't know what these numbers exactly refer to other than higher is worse, but assuming they are all taken with nr set similarly, why does the k-x look superior?

Heck, the k-x is almost as good at 6400 as the k30 is at 1600iso!

And why does the older k5 look better than the K30 with - I thought - the same sensor?

12-15-2012, 07:28 PM   #2
Site Webmaster
Adam's Avatar

Join Date: Sep 2006
Location: Arizona
Photos: Gallery | Albums
Posts: 43,140
If you really want to crunch numbers, I think the most reliable source would be DxO.

The reason the K-5 does better than the K-30, despite having the same sensor, is that the K-5 has 14-bit RAW, and Pentax may have also made tweaks to the K-30's image processing algorithms.
Attached Images

Adam Webmaster (Site Usage Guide | Site Help | My Photography)'s high server and development costs are user-supported. You can help cover those costs by donating. Or, buy your photo gear from our affiliates, Adorama, B&H Photo, or Topaz Labs, and get FREE Marketplace access - click here to see how! Trusted Pentax retailers:

12-15-2012, 09:36 PM   #3
Site Supporter
kiwi_jono's Avatar

Join Date: Dec 2009
Location: Christchurch, New Zealand
Photos: Gallery | Albums
Posts: 1,085
I don't have the K-30, but I have a K-x and K-5 and I have done some controlled test shooting on outdoor and indoor scenes.

From pixel peeping (100% view) at high ISO (1600 - 12800) the K-5 is very close to the K-x (k-5 lower noise in dark blue areas but reds slightly better on K-x). It is not easy to compare subjectively because there are so many factors to take in to account (for example when noise reduction kicks in and camera sharpening etc). HOWEVER there is more detail in the K-5 images to work with, giving the K-5 an advantage.

From the sample images I have seen on DPReview I thought the high ISO images looked pretty similar between K-5 and K-30 but at default settings the K-30 appeared to be doing a bit more noise reduction (but I could be mistaken) .
03-28-2013, 04:58 PM   #4
Senior Member
Tord's Avatar

Join Date: Jan 2010
Location: Gothenburg, aka Göteborg
Photos: Gallery | Albums
Posts: 211
My personal experience is that the K-30 does a slightly better job at moderately high ISO (even if it doesn't go as far up as the K-5), but what really differs is the, in my mind, far better AF of the K-30. The K-30 has a more capable processor (inherited from the ugly duckling K-01), which could be the reason why. The rest (the quiet operation of the K-5 & K-7) is much more your K-x, including a noisy shutter!

03-28-2013, 05:12 PM   #5
Senior Member
Tord's Avatar

Join Date: Jan 2010
Location: Gothenburg, aka Göteborg
Photos: Gallery | Albums
Posts: 211
If you go to Pentax K-30 Review: Digital Photography Review and exchange the cameras compared to the K-30, to K-x, K-5 & K-5 II you will find that not until ISO 25600 the K-x has an advantage on the others. The K-30 feels best all the way till then, with the K-5 being the worst of them all. The difference isn't big, but it is there! At low ISO I can't see any difference between any of them, neither in the shade, nor in the brightly lit areas. The K-30 might be a tiny bit softer, but does a real good job compared to its brothers and sisters ;-)!
04-01-2013, 01:14 AM   #6
Veteran Member

Join Date: Dec 2010
Location: Manila
Photos: Gallery | Albums
Posts: 2,190
QuoteOriginally posted by Tord Quote
you will find that not until ISO 25600 the K-x has an advantage on the others.
But the K-x doesn't have ISO 25600....

I don't have the K-5 Classic, but I do have both K-x and K-5 IIs. I'm not sure about controlled tests or whatnot, but in my case of personal experience the IIs trounces my K-x at any situation, only being real close in ISO100 and 200.
04-01-2013, 05:13 AM   #7
audiobomber's Avatar

Join Date: May 2008
Location: Sudbury, Ontario
Photos: Albums
Posts: 6,684
DXOMark is the only credible place for evaluating sensor performance on noise, DR and colour. All other reviews I've seen are misguided. Some are evaluating based on jpegs, which masks and manipulates real performance. Most reviews don't properly normalize to the same resolution, so higher pixel densities look worse.

DXOMark results show K-5 and K-30 are pretty much identical and SNR is superior by 1/2 stop over the K-x, normalized to 8mp. At ISO 12800 they all converge.
05-19-2013, 04:44 PM   #8
Site Supporter
Spodeworld's Avatar

Join Date: Aug 2011
Location: New Joisey
Photos: Gallery | Albums
Posts: 1,240
Is the 1.1 EVS difference in dynamic range for landscapes between the k30 and k5 visually noticeable in practical terms?


  • 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, generation, k-x, k30, k5, noise, photography, reviews, sensor
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Similar Threads
Thread Thread Starter Forum Replies Last Post
New K30 seems to have high amounts of noise? jbot Pentax K-30 & K-50 4 09-17-2012 05:26 AM
Weird grinding noise - K-x maxwolfie Troubleshooting and Beginner Help 7 08-25-2012 05:17 AM
K-X strange audio noise paranoia23 Troubleshooting and Beginner Help 3 08-16-2012 09:55 PM
X-Pro or K30/K5 goldpopper Non-Pentax Cameras: Canon, Nikon, etc. 6 07-29-2012 01:02 AM
k-x noise WDWmom Pentax DSLR Discussion 11 05-29-2011 04:40 PM

All times are GMT -7. The time now is 05:17 AM. | See also:, 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?
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]