As the time is now right in the northern hemisphere for close up shots of insects, large depth of field landscapes etc. I thought I would raise the subject of diffraction for the benefit of those members who are unaware of it. Despite posting a link to cambridgeincolour tutorials a while ago I only really looked at this subject when considering a camera upgrade. Here is the link
http://www.cambridgeincolour.com/tut...hotography.htm
I did some checks with the D100 and saw the impact when using standard lenses on a nice sunny day at Well harbour and I was easily able to get to f22. D100 has a diffraction limit f11 and sure enough images started to noticeably degrade at f16. ( Combination of lens going soft and diffraction effect ) As I am checking out my old AIS lenses I have done some tests with the 55 micro. The D2X has a diffraction limit of f8. From these tests I have concluded that I will not go below f13 but shoot at less magnification and then crop the image when greater dof is required for a suject containg fine detail. I will also look up a link that Wolfie posted somewhere to a program that allows images taken at varying points of focus to be combined.
I have attached full frame and crops to show the effect. These have not had any sharpening applied.
The major benefit of this knowledge as I see it, is that where very fine detail is involved, reasonably staying within your diffraction boundries limits the amount of sharpening required in post processing. Which can only be a good thing for overall image quality.
Don