[BigMackCam]

So, I just picked up a cheap and barely-used Samsung NX11 mirrorless camera to play with. It produces nice RAW images and I'm very pleased with it... but, I notice that even at base ISO 100, there is a certain amount of colour noise visible in shadows (with zero colour noise applied reduction in Lightroom). It's easily removable - in fact, Lightroom's default Color:25 noise reduction deals with it completely. But, I find it interesting, as my "earlier-vintage" CCD-based Pentax and Samsung cameras don't seem to suffer from this to anything like the same extent.

I think (though I'm not entirely sure) that the NX11 uses the same 14.6Mp CMOS APS-C sensor as the Pentax K20D, and so I'd be fascinated to examine some RAW files from the K20D - especially those that contain significant shadow areas. Alternatively, I'd be grateful for qualified assessments from those who shoot (or have shot) RAW with K20D as to whether there is any colour noise at base ISO.

Thanks in advance

---

Last edited by BigMackCam; 11-09-2017 at 05:03 PM.

[enoeske]

So, I just picked up a cheap and barely-used Samsung NX11 mirrorless camera to play with. It produces nice RAW images and I'm very pleased with it... but, I notice that even at base ISO 100, there is a certain amount of colour noise visible in shadows (with zero colour noise applied reduction in Lightroom). It's easily removable - in fact, Lightroom's default Color:25 noise reduction deals with it completely. But, I find it interesting, as my "earlier-vintage" CCD-based Pentax and Samsung cameras don't seem to suffer from this to anything like the same extent.

I think (though I'm not entirely sure) that the NX11 uses the same 15Mp CMOS APS-C sensor as the Pentax K20D, and so I'd be fascinated to examine some RAW files from the K20D - especially those that contain significant shadow areas. Alternatively, I'd be grateful for qualified assessments from those who shoot (or have shot) RAW with K20D as to whether there is any colour noise at base ISO.

Thanks in advance

Not the same sensor. I believe it was the GX10 and GX20 that where rebadged pentaxes (K10d and K20d, respectively). The K20d had a 14MP sensor.

[BigMackCam]

Not the same sensor. I believe it was the GX10 and GX20 that where rebadged pentaxes (K10d and K20d, respectively). The K20d had a 14MP sensor.

Apologies, I should have been more exact... the NX11 sensor is 14.6Mp, and I thought the K20D also used a 14.6Mp Samsung sensor? Or maybe it was the K-7

EDIT: I've edited my original post for accuracy.

[twilhelm]

Yes the K20 had a 14.6 megapixel CMOS sensor. At base iso I didn’t have color noise in shadows, but as the iso climbed, the color noise would appear. It is the only Pentax digital camera I sold, so I no longer have it to provide you with a test shot. I would have to do some searching to find a shot with it. Frankly I liked the K10d images more, hence the reason I still have it.

[rangercarp]

I almost bought one last week, but it was gone before I got the chance...

[caliscouser]

I believe the K-7 also had the same sensor.

[jawsy]

Subjective observation but shadows on my K20D did have a noisier quality than my *isDS. Was never a problem though as you noted yourself. Never looked back once I started using the k20D.

[rgknief60]

Anyone have a K20D and Lightroom?

Hi Mike. My RAW files are archived, and will take some time to access. I do have an original JPG
that I think will illustrate the shadow noise of the K20D to which you refer.

The subject is the backlit observation tower at Peninsula State Park, Door County, Wisconsin.
It was taken with a Pentax-A* 300mm F4 lens. Distance from camera to tower is 1.23 miles.

The first image is an actual pixel crop of the original image. The second image is after processing
in Lightroom 6. The third image is the second enlarged 200% to better show the grain in the
shadows versus the sky. Hope this helps.

Roger


Crop of Original JPG


JPG after Processing


Processed JPG Enlarged 200% to show Grain