2) Over all it's preferably a camera that produce too sharp pics
than a camera that produce too soft pics because in the soft pics
are less details
Excuse me! This is plainly wrong.
If you do a low pass filtering of an image (softening if you like)
you will loose high frequency detail (such as edges or small
detail).
Sharpening is more or less a high pass filtering, often a
non-linear one to just sharpen edges (unfortunately also noise). It
increases contrast along edges and gives an
impression of being
sharper. In reality it is no magic, it can´t create details that
aren´t in the original data... (as you said). It is a function of
how the eye perceive the image as sharp due to high contrast
edges/detail that make this work.
But your conclusions are all wrong. The CAMERA doesn´t do ANY low
pass filtering to make the "softer" images, it just doesn´t do as
much
sharpening ! So, even with the camera set to the lowest
setting, ALL detail IS there. Theoretically MORE detail is there
without sharpening!
It is NOT preferable to have a camera doing too much sharpening!
You can NEVER UNDO an oversharpened image! You can do low pass and
make the image blurry and thus decrease the impact of the
oversharpened edges but when you do you will at the same time
destroy other information in the image!
On the other hand, if the camera do little or NO sharpening at all
the images from the camera will look a little soft, but it is EASY
to sharpen them in photoshop! You can of course do a much better
job at filtering and sharpening in photoshop or other programs than
is possible to do in the camera (with little program space, little
processing time, etc).
So, please don´t confuse a "low sharpening" setting in a camera
with low pass filtering, it isn´t done that way. If you switch of
sharpening completely in a digital camera this will be the same as
film (where you of course don´t have any sharpening algorithms
available in the camera).
