Depth of Field with Macro Photography
The Depth of Field is the part of the photograph that is in focus. All that other stuff that is blurry in the foreground or background is out of the Depth of Field. The Depth of Field is very shallow with Macro Photography. To increase the Depth of Field, or the amount of the flower that is in focus, use a smaller aperture. Using small apertures from f/8 to f/16 help get more Depth of Field.
The sweet spot of a lens aperture is usually at f/8. The sweet spot is the aperture that most camera lenses will produce the sharpest focus. For example, most lenses take sharper photographs at f/8 then at f/22 or f/2.8. Using apertures in the middle produces sharper photographs. You will get more Depth of Field with a small aperture like f/22 but the lens won’t be at its sharpest performance. One reason is diffraction. Most point and shoot digital cameras don't go more then f/8.