I was out this weekend taking photos at a deer park, Calke Abbey in Derbyshire and discovered a strange effect on my images.
Firstly, to explain Bokeh. Bokeh is the quality of the unfocused part of the image and it should be soft and unobtrusive it certainly should not draw the eye from the focused subject.
I noticed when using my 70-300mm ED Nikonr lens I got some quite horrible stripes appearing in the bokeh, here’s an example.
It’s easier to see the effect when zoomed in closer in the following example
Bizarrely the fix for this problem I discovered after Googling around the subject was to remove the UV filter from the lens. This issue also seems to affect the newer VR version of the same lens, so if you have either of these Nikon lenses try shooting without a UV filter, and use a lens hood for protection instead.