Miket, depth-of-field has been discussed on this forum before so I you want you can look back for the previous discussions. Briefly, the CCD sensor is smaller than 35 mm frame size. This means that for the 7 series cameras a shorter focal length lens than would be used for a 35 mm camera will give the same field of coverage. Since 35 mm cameras are pretty much considered a standard Minolta has done us a favor by stating the focal length for the camera in 35 mm camera equivelents. The true focal length of the lens is 7.2 - 50.8 mm (page 160 of the manual), which is equivalent to a 28 - 200 mm 35 mm camera lens.
The depth-of-field for a lens increases as the focal length decreases - BUT ONLY FOR A FIXED IMAGE SIZE. Since the image of the 7 is smaller than that of a 35 mm camera it turns out that the depth of field is the same as it would be for a 35 mm camera with the equivalent focal lenth lens. What this means is that for all practical purposes just pretend that you are shooting a 35 mm camera and you will do fine on depth-of-field.