Re: Trying to reduce depth of field. Mark: The wider the aperture (in other words, the smaller the f-number - 2.8 is wider than 5.6) the shallower will be the depth of field, hence the easier it will be to separate your subject.
A second factor influencing depth of field is focal length. The closer you get to the telephoto end of the lens, the shallower will be the depth of field.
Considering these two factors, the best separation would be achieved with a wide aperture and a long focal length. With my camera (Minolta Z1) that would mean 10X focal length and f 2.8. A factor that mitigates against the ability of you camera to achieve this effect is autofocus. Auto focus tries it's best to get things into focus. If you have manual focus, you can focus on your desired center of interest while throwing the other stuff out of focus. Summing up, ideally you want a camera with a wide aperture, a long focal length, and the option of manual focus.
Sorry to be so wordy, but chapters, perhaps volumes, have been written on the subject.
Number - in this case f2.8), then zoom in as much as I can (10X in my S5000), and hopefully that will have the desired effect? I will try that in the morning as I have tried before with a wide aperture but have yet to zoom in as far as I can. Thanks for the advice Mark..
And to use the autofocus lock to choose what object I wish to have as the centre of focus..
Sounds right to this humble shutter bug.
Let us know how it turns out.
Manipulating depth of field as with a 35mm film camera is difficult, approaching impossible, with most digicams. They are equipped with very short focal length lenses (as in real focal lengths, not 35mm equivalents). So while there is some ability to control depth of field, as in opening the lens to it's widest settings (f2.8 isn't that wide), working at longer focal lengths, and working with focus point, separation of subject and background, etc., you won't be able to have as marked results as are possible with the longer focal lengths used on larger sensor cameras or with film...