Originally posted by Kiparisas I understand there might be some digital noise, but isn't it this a bit too much for a 100% crop on K-3 ii? Would appreciate your insights.
Hi,
My understanding is that digital noise is fairly common in blue skies and possibly in other areas of uniform colour. It might be due to the RGB Bayer filter configuration, in which only 25% of the photosites are filtered to blue. The demosaicing approach also affects the quality of the blue areas.
Coincidentally, I was just processing a couple of my images that have significant areas of bright blue sky. At ISO values of 100 and 200, I noticed speckles similar to your images. A modest, light-handed noise-reduction approach cleaned it up nicely.
The RAW developer app that I use -- RawTherapee -- has a one-touch setting to 'reduce artifacts in blue sky', which works okay but can introduce artifacts elsewhere. I use a combination of noise reduction and contrast control to manage low-ISO noise.
I shoot with a K-3 II, and have also noticed some 'blue-sky speckles' in my earlier K-5 II images, although to a lesser degree.
- Craig