fuji finepix f420 focussing problem?

Possibly the lens is not opening fully - have you dropped it but could also be dirt/ grit in the lens mechanism -
I have solved a couple of these dirt problems by blowing compressed air around the lens when it is opening (can use a petrol station forecourt machine )
Another trick is to Fully charge the battery and Try switching on and zooming at the same time - ( this activates the auto zoom sequence ) keep repeating this

pc6493
October 2009