Hi,

I have just got the same problem with my L 55-300mm. I have purchased 55-300mm lens together with my camera and basic 18-55mm lens. It was working fine with UV filter before. However after my last visit in London I have found that my lens is not focusing as sharp as it was before with or without UV filter. Only when I set up aperture at F32 (full depth) it focuses well, otherwise a picture looks blur and bad quality... I loved this lens for portrait pictures catching people unexpectedly. But now it is just useless. Any advices what have happened to my lens? Btw, what lens would you recommend for replacement? Good but not expensive? Or is it broken and might be repaired?