[slip]

Hope this hasn't been posted yet
Pentax K-3 image quality analysis: Does the K-3 clobber the K-5 II and the rest of the competition?

Enjoy!

Randy

[Drake Avenue]

That Olympus is surprisingly good.

[Parry]

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.

[Na Horuk]

Pretty sure the colour red is a problem for all bayer-sensor digital cameras, and it depends a lot on the processing (and calibration of the monitor the viewer is using). Nikon's D7100 being "far superior".. dunno, I dont see it at all

[Ahab]

Pretty sure the colour red is a problem for all bayer-sensor digital cameras, and it depends a lot on the processing (and calibration of the monitor the viewer is using). Nikon's D7100 being "far superior".. dunno, I dont see it at all

Neither do I.

[JimmyDranox]

Sensibility of the sensor is one thing. Generally much smaller on red. I saw the same problem on Sony A7R. Nikon 7100 has Toshiba sensor, if I'm not mistaking.

On the other hand, I've done some test on some K-5 pictures from Imaging Resources, and the red details are there, but needs some PP to see it. Latter I will post the image.

[JimmyDranox]

This are the images from Imaging Resources, K-5 at 12800 ISO. First unprocessed, second and third processed in different degrees. Crop at 100%.

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Last edited by JimmyDranox; 04-17-2017 at 10:27 PM.

[danny09]

D7100 looks very good in the details department IMO. Reds has always been a problem for Pentax post K10D I guess. But we can see Nikon handling Reds very well dating back to their D40. Assuming Pentax and Nikon and Sony source their sensor from same manufacturer (i.e Sony) how can they handle Reds better than Pentax? It sure doesnt sound to be a sensor issue per se. Could it be the Image processing circuitry after the image has been acquired by the sensor?
From their image quality tests it appears K5IIs holds it own really well against the K3.
Once someone posts pictures of red fabric detail being recovered in PP, we will know more details!

[SteveB]

Pentax jpgs have too much colour noise reduction combined with high red saturation in default Bright mode, that's what blanks out the red cloth detail in the IR images. RAW, no problem - in fact exceptionally good.

[danny09]

Thank you very much Jimmy for posting the processed crops! However the magenta hue that K3 imparts to the cloth fabric next to the red cloth is still there. That can not be undone I guess. But your images confirm that one can preserve red 'detail' if shot in RAW.

[danny09]

Also what is your image processing setup and settings for noise reduction?

[JimmyDranox]

I used Raw Therapee. But just a few days. I still have to learn to find the best balance between luminance, chrominance, delta red and blue, in noise reduction. As you can see, i recovered the red details, but I lose some in green and blue.

[danny09]

Thanks. I use Raw THerapee too but it freezes on me so many times Also you could recover the red detail but look at rest of the image, it actually lost the detail in light green and dark blue adjoining cloths! Maybe somewhere in the Raw Therapee details...?

[JimmyDranox]

Same image processed in DxO Optics Pro 9, noise reduction PRIME, luminance, chrominance, and low frecquency at 85, dead pixel at 24. I am still trying to learn, and to find the best program. Yes, I said before, I lose details in green and blue in those images processed in Raw Therapee. It's a very powerfull program, but is big, and there are a lot of controls to learn. On my laptop is working well, except when i want to save in Tiff at 16 bits.

[Parry]

Pentax jpgs have too much colour noise reduction combined with high red saturation in default Bright mode, that's what blanks out the red cloth detail in the IR images. RAW, no problem - in fact exceptionally good.

Thanks Steve. I only shoot in RAW. That Imaging Resource test shot near put me off buying a K-3. For those who shoot JPEG the quality of that image is frankly unacceptable. Perhaps Pentax can do something with a firmware update.