FZ200 NR and sharpening - my theory and experiments to date-Part 1

This is going to be sort of long, so I'll do a two part.

I'd also like feedback on my thoughts here.

First some background and definitions that will be needed for the rest of the thread and in Part 2  Note this is specific to the FZ200; but may apply to other cameras, at least in part.

NR - short for noise reduction.  The camera's attempt to reduce noise in the images.  Most cameras have some form of automatic or intelligent features in how the noise is identified and where it is applied and to what degree.  Noise reduction decreases sharpness as it tries to smooth out the noise.  In extremes, NR looks like a water color painting.  NR gets more aggressive with increased ISO settings.

Noise - Noise can be white speckles (luminance noise) or colored dots and blotches (chroma noise) that are not in the original.  There are two basic types of noise -  the first is thermal noise and is similar to the "snow" on a poor TV picture.  The second is read noise, and is generated by the camera accessing the data off the sensor.  Thermal noise builds up over time, so it will be more apparent with longer exposure times (slow shutter speeds).   Noise is also more easily seen against smooth one color areas, where the light is low, where contrast in lighting and subject is low, and in darker areas where the signal to noise ratio is lower, and at high ISO.

ISO - What we refer to as ISO is a carry over from film where the sensitivity of film to light was rated as an ISO number.  In digital, the sensor has a base sensitivity, corresponding to some ISO rating.  At higher ISO settings in the camera, the sensor sensitivity does not change; but the signal from the sensor is amplified more, just like turning up the volume control.  However, this means that the noise generated is also amplified.  So high ISO settings are inherently more noisy.

i Resolution - a feature of some Panasonic cameras, and found on the FZ200.  It is an intelligent application of sharpening based on the image parameters, subject material, ISO, etc.  It will do only as much as the analysis of the image dictates; adding more sharpening at higher ISO and in low light.  Also, it is not applied to smooth areas of constant color, as in the sky, so it avoids the mottled appearance and small sharpening artifacts as often seen in use of regular sharpening.

OK, this ends Part 1.

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Jerry