<< just bought the ViewSonic A90f 19 inch monitor, the picture isn't very sharp >>
I presume you tried normal things like deguass etc,anyway I had that problem with my 2nd replacement for my first RMA one(geometry problem),I phoned them up and told them the replacement one was slightly out of focus and they picked it up and gave me a replacement,if you are sure it`s a focus problem then RMA it,no point in hurting your eyes.