BOKEH

This is probably a silly question but what is BOKEH or rather what does it stand for? (TLAs I can cope with but 5!)

Kim,

Bokeh is not a 5TLA It is the effect produced when out-of-focus bright light hits the lense. The term comes from Japanese ( http://www.minox.org/minoxencyclopedia/b/bokeh.html )

Here's a definition:
http://www.kenrockwell.com/tech/bokeh.htm

And different lenses really do have different bokeh. My Pentax 50mm/f1.7 produces a lovely effect that just seems 'harder' on my Tokina lenses.

Hope that clarifies it!
Matt