I have had my D300 for over a year now it's been back to nikon for repair 3 times for focusing issues.
When i shoot an image at f11 everything looks sharp when i shoot the same image at f22 it looks soft all over the image. i understand diffraction and f22 will not be as sharp as f11 but what i'm seeing is not right. it's like you took your f11 shoot and applied the photoshop filter more blur to it.
So what i'm asking if any of you could help by shooting an image at f11 and the same image at f22 and compare the difference and is it as drastic as to what i'm seeing.

thank you for your help in advance.

Im not a expert and have a d300 so i would help you out. But maybe its a bad lens.. What lens are you using? Even a good lens can can be a  lemmon. Can you change the lens and test it again? If you don't have a extra lens find a camera store that would maybe let you use one or see if you can find a friend with another nikon lens..

I did a few shots and posted them on my site.. here is the link for the section Test Photos  you can see all data of the photos there and you can download the full files. I took 2 f11 and 2 f22 and 1 2.8. the lens is a sigma 18 to 50mm 2.8 HSM macro.

What lens?



Most lenses are much worse at f/22 than f/11.



http://www.cambridgeincolour.com/tutorials/diffraction-photography.htm



http://www.earthboundlight.com/phototips/diffraction-small-apertures.html?source=rss