Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
01-12-2014, 07:08 PM - 1 Like   #61
Pentaxian
Class A's Avatar

Join Date: Aug 2008
Location: Wellington, New Zealand
Posts: 9,176
QuoteOriginally posted by audiobomber Quote
Strictly speaking, your statement is correct. A raw file is unaffected by camera settings.
This is not entirely true.

For instance, if you opt for dark frame substraction as a camera setting (referred to as "long exposure NR" or similar) then this will irrevocably affect the RAW data.

I also suspect that other NR settings also affect the RAW data but I haven't verified this as I just set every in-camera processing to "off" so that I have all options in post-processing.

BTW, it is well-know that Pentax applies some non-optional NR to RAW files with the K-5 beyond ISO 1600. If they have changed the strength of this "smoothing" (as DxOMark calls it) for the K-3 then this could be misinterpreted as a noisier sensor, even though Pentax just did the right thing and eased off on the compulsary NR.

Noise should always be judged with a view to the captured detail as well. It is not that hard to deliver a noise free image with all details smeared. In other words, one should not hold it against the K-3 if it retained more noise in order to maintain details.

Even DxOMark does not look at resolution in the context of evaluating noise, so clearly a fair comparison isn't that simple.

01-13-2014, 04:15 AM   #62
Site Supporter




Join Date: Mar 2009
Location: Gladys, Virginia
Photos: Gallery
Posts: 16,009
QuoteOriginally posted by normhead Quote
Amazing images.... now if I was there with you, I'd have more idea, if it's just my camera, or it was my shooting conditions were not as favourable. Your shooting situation had bright lights and high contrast, mine the whole histogram filled half to 3/4s of the window, so very low contrast. The contrast function I used ( About +10) accentuated the noise, where as I'm guessing you had all the contrast you needed in your original image, just a guess, so probably much lower contrast setting.
I just wonder, Norm, if part of the issue is the lack of RAW support from Apple. I struggled a lot with editing K3 files initially, until Adobe came out with support for them. Certainly the files require very different processing from K5 files (probably a lot closer to processing for the K5 IIs).
01-13-2014, 08:08 AM   #63
Pentaxian
audiobomber's Avatar

Join Date: May 2008
Location: Sudbury, Ontario
Photos: Albums
Posts: 6,676
QuoteOriginally posted by Class A Quote
BTW, it is well-know that Pentax applies some non-optional NR to RAW files with the K-5 beyond ISO 1600. If they have changed the strength of this "smoothing" (as DxOMark calls it) for the K-3 then this could be misinterpreted as a noisier sensor, even though Pentax just did the right thing and eased off on the compulsary NR.
DXOMark signifies noise "smoothing" with hollow dots on the SNR graph. They are clearly visible on all the K-5 family bodies, at ISO's above 1600. There are no hollow dots on the K-3 SNR graph, which indicates that DXO did not find non-defeatable raw NR in the K-3 files.

The SNR graphs for the K-5 family and K-3 are virtually on top of one another until ISO 1600, where they diverge by 1/2 stop. They equalize again at ISO 12800. Clearly if the K-5 raw noise were not manipulated, 16 and 24MP SNR's would be identical.
01-13-2014, 09:24 AM   #64
Site Supporter




Join Date: Mar 2009
Location: Gladys, Virginia
Photos: Gallery
Posts: 16,009
QuoteOriginally posted by audiobomber Quote
DXOMark signifies noise "smoothing" with hollow dots on the SNR graph. They are clearly visible on all the K-5 family bodies, at ISO's above 1600. There are no hollow dots on the K-3 SNR graph, which indicates that DXO did not find non-defeatable raw NR in the K-3 files.

The SNR graphs for the K-5 family and K-3 are virtually on top of one another until ISO 1600, where they diverge by 1/2 stop. They equalize again at ISO 12800. Clearly if the K-5 raw noise were not manipulated, 16 and 24MP SNR's would be identical.
In use, the cameras are really close. And that's what DXO Mark says. There is some difference in the numbers in the middle ranges between 200 and 800 isos, but it isn't probably visible in the real world.

01-13-2014, 10:08 AM   #65
Pentaxian
audiobomber's Avatar

Join Date: May 2008
Location: Sudbury, Ontario
Photos: Albums
Posts: 6,676
QuoteOriginally posted by Rondec Quote
In use, the cameras are really close. And that's what DXO Mark says. There is some difference in the numbers in the middle ranges between 200 and 800 isos, but it isn't probably visible in the real world.
I'm not sure what you're looking at. The SNR graphs are exactly coincident from ISO 100 to 1600.
Pentax K-3 versus Pentax K-5 IIs - Side by side camera comparison - DxOMark
01-13-2014, 11:04 AM   #66
Site Supporter




Join Date: Mar 2009
Location: Gladys, Virginia
Photos: Gallery
Posts: 16,009
QuoteOriginally posted by audiobomber Quote
I'm not sure what you're looking at. The SNR graphs are exactly coincident from ISO 100 to 1600.
Pentax K-3 versus Pentax K-5 IIs - Side by side camera comparison - DxOMark
SNR curves are the same. The dynamic range curves are somewhat different.
01-13-2014, 07:35 PM   #67
Veteran Member




Join Date: May 2008
Location: SF Bay Area
Posts: 417
QuoteOriginally posted by john5100 Quote
Normhead, Ash, and saladin, Thank you

Just the opposite. It was extremely dark with moving subjects. It was so dark that my KX had a hard time focusing and at some points it didn't focus. The K3 just powered forward and didn't slow down.

I shot another show last night where many of my photos were at ISO 16,000 in TAV mode. I have spend so much time in the dark shooting shows that I think I have LR4 noise reduction down. I edited 900 photos in 2 hours.

Saladin - you are right. It is a complete system that makes the difference. As some of you have seen, my KX has rocked as a concert camera but my K3 is leaps and bounds ahead of it.
John
Amazing shots especially those >ISO 8000. What lens did you use for those shots? Also your signature doesnt include your current sweetheart i.e K3 :-P
01-13-2014, 08:05 PM   #68
Pentaxian
audiobomber's Avatar

Join Date: May 2008
Location: Sudbury, Ontario
Photos: Albums
Posts: 6,676
QuoteOriginally posted by Rondec Quote
SNR curves are the same. The dynamic range curves are somewhat different.
We were talking about noise.

01-13-2014, 10:47 PM   #69
Pentaxian




Join Date: May 2008
Location: Seattle, WA
Posts: 1,376
Hi Danny,

Thank you, I used my DA* 16-50mm F2.8 and my DA* 50-135mm F2.8

I got to photograph and interview Martha Davis with The Motels on Saturday night.

ISO 12,800




ISO 16,000

Last edited by john5100; 01-13-2014 at 11:17 PM.
01-17-2014, 11:08 AM   #70
Forum Member




Join Date: Sep 2010
Posts: 63
QuoteOriginally posted by john5100 Quote
Okay, I re-edited my photos from Friday and they turned out much better...see these photos.

Last night I shot the 80's band, The Motels, using TAV mode and the K3 rocked. The venue was super dark and the camera chose ISO 16,000 which I was very nervous about. No need to be...wow I am so impressed. This K3 is wonderful in low light. I tried using my previous concert camera, my KX, it wouldn't focus in that light. The K3 never had any trouble.

ISO 12,800


ISO 10,000


ISO 10,000
Hi John,

Cool live shots, i bridle my k3 at 6400 max 'cose i don't want so much noise on concert report and i'm surprised that u present a so clean shot at 12.800 !
but u said ISO 12,800 while in fact it's ISO 6400 as i can see on u're website, so why ? is it an estimation of the black parts of the image ?
Back Beat Seattle | Photos and Review: Paula Boggs Band @ The Skylark Cafe

Last edited by novsky; 01-17-2014 at 11:20 AM.
01-17-2014, 12:03 PM   #71
Pentaxian




Join Date: May 2008
Location: Seattle, WA
Posts: 1,376
novsky

For the ones that you are referring too, I under exposed by 1 stop and then pushed it 1 stop in software to ISO 12,800.

This one is straight ISO 16,000. Wasn't planned. This was a mistake.


Exposure 0.003 sec (1/320)
Aperture f/4.0
Focal Length 18 mm
ISO Speed 16000


and this one is actually ISO 12,800

Exposure 0.01 sec (1/100)
Aperture f/3.2
Focal Length 85 mm
ISO Speed 12800

Last edited by john5100; 01-17-2014 at 12:24 PM.
01-17-2014, 12:41 PM   #72
Forum Member




Join Date: Sep 2010
Posts: 63
Thanks, for u're answer.....

So, i'm always at -1 -0.7 Ev, my 3200 and rarely 6400 ISO shots are in fact respectively at 6400 & 12800 .... I'd never think about that ;-) ^_^
01-17-2014, 01:07 PM   #73
Pentaxian




Join Date: May 2008
Location: Seattle, WA
Posts: 1,376
In truth, my main concert camera used to be my KX and I shot that below ISO 5000 too. I'm still trying to get used to the K3 and I mistakenly shot that high. The saving grace was that the K3 is so great at high ISO that it saved me.
01-17-2014, 03:17 PM   #74
Pentaxian
audiobomber's Avatar

Join Date: May 2008
Location: Sudbury, Ontario
Photos: Albums
Posts: 6,676
QuoteOriginally posted by novsky Quote
Thanks, for u're answer.....

So, i'm always at -1 -0.7 Ev, my 3200 and rarely 6400 ISO shots are in fact respectively at 6400 & 12800 .... I'd never think about that ;-) ^_^
Exposing at -1EV and ISO 3200 is still ISO 3200. If you push the exposure one stop with your post-processing software, then it is equivalent to ISO 6400.
01-18-2014, 04:48 AM   #75
Forum Member




Join Date: Sep 2010
Posts: 63
QuoteOriginally posted by audiobomber Quote
Exposing at -1EV and ISO 3200 is still ISO 3200. If you push the exposure one stop with your post-processing software, then it is equivalent to ISO 6400.
Yessss I know ;-), it was a "question" about comparative High ISO results, a post-processed 6400 may/must be announced as a 6400 ?! No ?
Particularly in post like K3 vs K5, we can't say "hey, look at K3 12800 ISO" that's in fact a 6400 one...right ?
it's not a "lawsuit" about your beautiful shots John, just a question about how to present High ISO results ;-)
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!
dslr, images, k-3, k3, k3 vs k5, k5, k5 high iso, pentax k-3
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
New K3 vs K5ii high iso RAW tests ihasa Pentax K-3 8 11-04-2013 09:15 AM
DR/Noise performance: pushing exposure vs high ISO HSV Photographic Technique 8 03-12-2013 06:51 PM
K-R VS X100 High Iso Noise Comparison Ryan Cole Pentax DSLR Discussion 20 02-01-2013 02:36 PM
K5 High ISO Noise Reduction Setting daphnejohn Pentax K-5 2 11-06-2011 07:45 PM
High ISO Noise vs. Underexposure Correction yoon395 Photographic Technique 7 08-27-2011 06:13 AM



All times are GMT -7. The time now is 04:43 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