>> I'm guessing he's not seeing diffraction effects as much
>> as sensor noise. Diffraction is a rather subtle effect, and
>> unlikely to be a major issue at f/14.

> I'm afraid, diffraction could be the major issue at f/14.

I haven't anyone mention ... diffraction is related to the
absolute size of the aperture (the "stop" formed by the iris)
inside the lens.  That aperture is commonly expressed as a
ratio based on focal length. (*)

The absolute aperture size is the same with a 14mm lens at f/14
(e.g. point & shoot camera) or with a 100mm lens at f/100 (e.g.
Digital Rebel XT with common Canon macro lens).

Unless you know the focal length of the lens AND the f/stop, you
can't draw reasonable conclusions about diffraction effects.

						Lee

(*) It was found early on (circa late 1800's) that lens behavior
    in terms of exposure and depth of field was based on this
    relative ratio, not absolute size of aperture.

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