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11-26-2011, 09:17 PM   #1021
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QuoteOriginally posted by mojoe_24 Quote
How does the K-5 and the K-x compare for higher iso shots? I'm always scared to go too high on my K-x.
Well I can't speak for the entire sensitivity range because I rarely shoot above ISO6400. Though that sensitivity(6400) I'd say that they are very close in performance. However the K-5 gain an edge with its slightly resolution and noise characteristic(finer grain). Though I think both could be coaxed into very similar image quality when all is said and done. This is of course... based on RAW performance. If were talking JPG, then I wouldn't recomment either or based on the terrible detail loss produced by camera NR.

Hope this helps.

11-27-2011, 12:54 AM   #1022
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Mojoe_24, That's exactly the same question that I have too. Love to see a comparison some time.

John Bee and Savoche - The kitten and leopard photos are great! Well done

This is the K200D at ISO 1600


This is the KX at 1600


KX at ISO 5000

Last edited by john5100; 11-27-2011 at 01:39 AM.
11-27-2011, 04:20 AM - 1 Like   #1023
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Pentax K-7 with F 80-200 at ISO3200
11-27-2011, 06:59 AM   #1024
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QuoteOriginally posted by mojoe_24 Quote
How does the K-5 and the K-x compare for higher iso shots? I'm always scared to go too high on my K-x.
QuoteOriginally posted by john5100 Quote
Mojoe_24, That's exactly the same question that I have too. Love to see a comparison some time.
DXOMark allows you to compare raw performance: low-light ISO is the highest ISO setting for a camera that allows it to achieve an SNR of 30dB while keeping a good dynamic range of 9 EVs and a color depth of 18bits.
A difference in low-light ISO of 25% represents 1/3 EV and is only slightly noticeable.


K20D = ISO 639
K-x = IS0 811
K-5 = ISO 1162

DxOMark - Compare cameras side by side

DPR has test photos for comparison. You select the K-5 ISO you want, then select K-x results in the drop down menu instead of D7000 or 7D:
Pentax K-5 Review: 20. Compared to (RAW): Digital Photography Review

Sample jpegs from Imaging Resource, NR off (click on the jpeg for full resolution):

K-x, ISO 6400
http://216.18.212.226/PRODS/KX/FULLRES/KXhSLI06400_NR0.JPG

K-5, ISO 6400
http://216.18.212.226/PRODS/K5/FULLRES/K5hSLI06400_NR_0.JPG

Caution, the samples in the IR Image Comparometer are virtually useless for comparing noise. They use camera defaults for the jpegs; some cameras apply no noise reduction, some apply a little, some apply a lot.

Bottom line, the K-5 has better noise performance than the K-x by just under half a stop. The best place to compare IMO, is the SNR 18% graph shown on DXOMark.


Last edited by audiobomber; 11-27-2011 at 07:07 AM.
11-27-2011, 11:30 AM   #1025
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K-5 iso 10,000 In-Camera JPEG in poor light.

Only Resized. Note Exif for poor light. I think for in-camera jpeg the dynamic range is fabulous in handling the bright and shadows. Also, the images still maintain their texture with metal still looking like metal and not plastic.






11-27-2011, 08:36 PM   #1026
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Do you guys have any tips to getting good high iso performance? I've taken some 1600 that have more noise than some of these 6400 pictures.
11-27-2011, 08:46 PM   #1027
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QuoteOriginally posted by mojoe_24 Quote
Do you guys have any tips to getting good high iso performance? I've taken some 1600 that have more noise than some of these 6400 pictures.
The first and foremost recommendation I'd have for this is to expose your subjects just short of blowing your highlights.

The second thing I'd recommend is to shoot RAW. You will gain much more control over NR processing in RAW than with JPG images.

And the third and final thing I'd add would be to develop a good noise reduction method. And for this I'd
recommend a good software like Topaz Denoise which I believe is the most advanced NR software in production imo.
11-27-2011, 09:28 PM   #1028
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I only shoot RAW. I'll have to look into Topaz Denoise though. I only have LR and Photoshop right now.

11-27-2011, 09:55 PM   #1029
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QuoteOriginally posted by mojoe_24 Quote
I only shoot RAW. I'll have to look into Topaz Denoise though. I only have LR and Photoshop right now.
NP. Topaz Denoise works in both platforms, though I prefer using it with Photoshop as it allows for mode advanced edit(using layers etc).

Hope this helps/.
11-28-2011, 11:38 AM   #1030
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Pentax K-7 ISO 2500 F80-200
11-28-2011, 04:17 PM   #1031
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iso 12800, in-camera jpeg with NR at low, only resized.



11-28-2011, 06:54 PM   #1032
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QuoteOriginally posted by audiobomber Quote
DXOMark allows you to compare raw performance: low-light ISO is the highest ISO setting for a camera that allows it to achieve an SNR of 30dB while keeping a good dynamic range of 9 EVs and a color depth of 18bits.
A difference in low-light ISO of 25% represents 1/3 EV and is only slightly noticeable.


K20D = ISO 639
K-x = IS0 811
K-5 = ISO 1162
It's good for people to see real numbers that represent controlled comparisons like this from time to time, as it is way too easy to get fooled by Seeing random images of different scenes taken with different settings and processed in different ways and draw entirely incorrect conclusions from them. For instance, it used to be pretty fashional for people to claim the K20D was at least a stop or two better the K10D, that the K-x was easily two stops better than the K-X, and the K-5 another stop or two better still. That might lead someone to conclude the K-5 is like 4-6 stops better than the K10D. But the numbers show the difference to be just barely over one stop. I don't know that there are many people who would accept that those numbers are accurate in this particular case, but overall, most comparisons I've made in real life come out to show all cameras within one stop of each other.
11-28-2011, 07:24 PM   #1033
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QuoteOriginally posted by Marc Sabatella Quote
It's good for people to see real numbers that represent controlled comparisons like this from time to time, as it is way too easy to get fooled by Seeing random images of different scenes taken with different settings and processed in different ways and draw entirely incorrect conclusions from them. For instance, it used to be pretty fashional for people to claim the K20D was at least a stop or two better the K10D, that the K-x was easily two stops better than the K-X, and the K-5 another stop or two better still. That might lead someone to conclude the K-5 is like 4-6 stops better than the K10D. But the numbers show the difference to be just barely over one stop. I don't know that there are many people who would accept that those numbers are accurate in this particular case, but overall, most comparisons I've made in real life come out to show all cameras within one stop of each other.
Well, the issue with the K10 isn't noise, it was banding (some K20s had issues with this too, some didn't). I just really found with my K10, that it didn't allow high iso due to that. I think the K200 was a lot more tolerant of high iso situations than the K10, even though it should have had the same sensor.

The k5 on the other hand is special compared to these other cameras. Its photos just don't fall apart, even if you have significant underexposure. You can push to iso 12,000 and not have the photo fall apart the way it would with a K10 or, K20. Sure, the dynamic range isn't there, but it is still more than usable. Per Dxo Mark, the K5 has dynamic range of 11 EV at iso 800, just a hair below what the K10 and K20 have at iso 100.

Last edited by Rondec; 11-29-2011 at 04:32 AM.
11-28-2011, 08:01 PM   #1034
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The DxOMark low-light scores describe the maximum ISO point where IQ is not technically degraded (SNR 30db, DR 9 EV's). Which is indeed really useful to know and informative.

However the DxO low-light ISO scores only represent the top of the IQ/ISO curve. The slope of the curve of DR and SNR degradation as ISO increases past those DxO low-light scores also needs to be considered. The K-x and K-5's IQ degrades quite slowly as ISO increases, whereas the K20D/K-7 (and the K200D) have a different, less extended curve, particularly past a certain point like 1600 ISO. This makes a difference to how high-ISO looks in those cameras.

Another thing I've noticed and seen in some test results is the ability of the Kx/K5 Sony sensors to hold onto resolution quite well as ISO increases, even as DR drains away, noise increases and the image becomes quite 'flat'. This makes a noticeable difference to the visual 'grain' structure of high-ISO images out of the K-x and K-5, which usually stays quite pleasing up into quite high ISO's.

So perhaps even if technically at the peak of their ISO/IQ curves there may only be a 1 stop difference between say the K20D and the K-5, the difference between the output of those cameras at high ISO's past the peak in the curve usually looks a lot more than 1 stop.

Last edited by rawr; 11-28-2011 at 08:06 PM.
11-28-2011, 09:20 PM   #1035
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QuoteOriginally posted by rawr Quote
The K-x and K-5's IQ degrades quite slowly as ISO increases, whereas the K20D/K-7 (and the K200D) have a different, less extended curve, particularly past a certain point like 1600 ISO. This makes a difference to how high-ISO looks in those cameras.
There is some clever manipulation going on with the files, as explained by DXO. Even with the manipulation, the K-x is only 2/3 of stop better than the K20 at ISO 6400. That's what the DXO sensor curve shows (6dB = 1 stop), and it matches my experience as a K20 and K-x owner.

QuoteOriginally posted by rawr Quote
Another thing I've noticed and seen in some test results is the ability of the Kx/K5 Sony sensors to hold onto resolution quite well as ISO increases, even as DR drains away, noise increases and the image becomes quite 'flat'. This makes a noticeable difference to the visual 'grain' structure of high-ISO images out of the K-x and K-5, which usually stays quite pleasing up into quite high ISO's.
No, there's no magic, just the numbers that DXO measures.
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