You're welcome, Andy.
You will only really notice diffraction softening at f/16 and smaller unless you examine everything at 100% ... Some people cannot help themselves, and become inveterate pixel peepers ... .The technical side sometimes gets me, but based on your info, essentially would I be correct in thinking that the kit lenses would be sharpest between say f/4 and f/8, and starts to get noticeably softer between f/8 and f/16?
Me, for instance ...
Canvas hides a multitude of sins ... . The sort of diffraction softening I mentioned would be noticeable in a finely detailed 17x22 inch print, but not in other scenes, even at that size.If so, I don't think it would be a deal breaker for me, normally shoot wildlife around f/7.1-f/8. Might just mean shooting with a lower f stop number or focus stacking for landscapes?
The majority of my photos are Facebook, forums, etc with the occasional 6x4 print or very rarely a 16x12 canvas.
No worries. Get in touch when it out-halfwits you!! I sometimes think that the bloody things are smarter than I am .Thanks again