Apologises,

The depth of field clearly shows my lack of knowledge, and using my words incorrectly. I thought that if you had a bigger maximum aperture lens i.e. f2.8 vs a smaller one say f3.5-4.5 it meant that you could shoot with a larger aperture and therefore get a smaller depth of field, however with a smaller aperture lens it means you would get a greater depth of field, i.e. like a compact camera. I wonder if the advice I was given was saying that it is best to go for a larger aperture lens because when you shoot at a couple of stops down (is that right terminology) it is crystal clear, therefore with the f2.8 it would be very good at say f4 whereas the f3.5-4.6 would be best at f6 or higher...is this the case.

I apologise if these are simple questions, however they are helping out no end.

Thanks again