Still a Newbie so apologies if this is a dumb question - I can see loads of posting about dust on sensors but none (when I searched) on dust in lenses. Just bought a used 18-70mm DX Nikon lens online and it has got a number of dust / fibres inside the lens. Have taked a few photos with high and low aperture setting and cant see any obvious effect of the dust / fibres in the lens - so should I be worried? I bought the lens 'cos it seemed a good deal for £105 inc Postage. But once I saw all the dust I felt a bit disappointed. I have bought 3 other used lenses from ebay / other used camera shops but none had anywere near this level of dust inside them - often no visible dust at all!