Bit quiet here so I've been looking at some of my bookmarks.
This Site was one I chanced upon. No idea where I got it from - but anyway.... there is some fascinating stuff there.
Edit: think it may have been from a thread about monitor calibration here some time.
If I am reading
this page right, images on the 20D will degrade above f11 due to diffraction. Airy disks sound like frisbees but define where this diffraction will come in and become visible.
Other sensor pixel densities will have the same problem but at different apertures.
So as your lens gets sharper with a smaller aperture your sensor starts to work against you because of diffraction
Can't see it amounts to much in real world use of the camera... but it's interesting stuff.
Oh and there are some items about sensor noise for SammyC too.
Anyone else got a good bookmark to share for the long evenings?