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11-10-2013, 12:56 AM   #16
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QuoteOriginally posted by Parry Quote
For those who shoot JPEG the quality of that image is frankly unacceptable.
Ummm, remember a few things:
- in camera JPG's are dependent on image tone settings and in-camera noise reduction settings. How the camera JPGs look will depend on how you tune those;
- we are talking ISO 12800 in some of these samples ...

Also the Imaging Resource test charts and this stuff about the reds have already been discussed a lot. The conversation started shortly after IR released their initial K-3 test samples - eg this 7 page thread:

https://www.pentaxforums.com/forums/172-pentax-k-3/240948-pentax-k-3-studio-samples-ir.html

11-10-2013, 03:03 AM   #17
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This is a crop of the IR RAW image at iso6400 converted in ACR 8.2 CS6 with -20 red saturation and all noise reduction turned off.......Edit - I posted this as an attachment and this site seems to have resized it to about 67%, weird ......
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Last edited by SteveB; 11-10-2013 at 03:09 AM.
11-10-2013, 03:19 AM   #18
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Here's another try, I think the 1280 pixel height was the problem. There's plenty of detail, it's the unsympathetic colour NR that's the issue with jpgs and even in ACR once you start using any......
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11-10-2013, 03:45 AM   #19
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Here's the Nikon D7100 RAW iso6400 with no NR in ACR, and no correction to red saturation as it's not needed. I think the K-3 wins by a country mile myself, it looks to me as if Nikon are using a lot of colour NR in RAW even when it's set to off................Edit:- see later corrected post

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NIKON D7100  Photo 

Last edited by SteveB; 11-10-2013 at 04:45 AM.
11-10-2013, 03:50 AM   #20
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QuoteOriginally posted by Parry Quote
Why can't the K-3 handle the colour red?

Perhaps my eyesight is on the way out, but I'm not blinded by fanboy ideology. The Nikon D7100 images look far superior.
Your eyesight is fine and you're completely right in pointing that out. And without spewing technoblable, the gist of it is that the Bayer sensors(most all of the sensors used in APS-C and FF camera's today) are not very adept at reproducing red channel detail.

Having said that, in knowing this, many manufacturers have taken it upon themselves to compensate for this in their in-camera processing. And thus, why Nikon has earned a reputation for their red channel tweaking. Which can come as a tradoff as it is often seen as having muted reds against the competition.

Anyways, all that to say that Nikon's red channel performance does indeed stand out(and in this case) by providing more detail in the red swatch than with the K-3 at base ISO.

Hope this helps.
11-10-2013, 03:58 AM   #21
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QuoteOriginally posted by SteveB Quote
Here's the Nikon D7100 RAW iso6400 with no NR in ACR, and no correction to red saturation as it's not needed. I think the K-3 wins by a country mile myself, it looks to me as if Nikon are using a lot of colour NR in RAW even when it's set to off................
Sorry to sound contradictory, but... that image most definitely has NR(chroma) applied to it. That being said, it's quite easy to overlook settings when processing in RAW and do I wouldn't worry about such oversights beyond that of helping out.

Thanks for sharing your observations btw.
11-10-2013, 04:42 AM   #22
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QuoteOriginally posted by JohnBee Quote
Sorry to sound contradictory, but... that image most definitely has NR(chroma) applied to it. That being said, it's quite easy to overlook settings when processing in RAW and do I wouldn't worry about such oversights beyond that of helping out.

Thanks for sharing your observations btw.
You're right, I went back and checked my ACR settings and even though colour NR had been set to zero, somehow it had turned itself back up to 25... here's the D7100 with all NR off at iso6400......
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11-10-2013, 10:25 AM   #23
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Thanks SteveB for posting the comparo. It certainly confirms that raw files coming straight out of camera for K3 are actually pretty good at ISO6400. The Red channel really is Pentax in camera image processing concern. Thirdly even though every manufacturer says their NR=OFF is no noise reduction but in reality everyone does perform some noise reduction .

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