He does mention that, yeah: > The smaller the focal length of the external lens and bigger - of built-in camera's optics, the greater magnification is achieved

He does mention that, yeah: > The smaller the focal length of the external lens and bigger - of built-in camera's optics, the greater magnification is achieved, but less depth of field is obtained. Compact camera, with a sensor of small physical size, have an advantage over DSLRs in the depth of field and mobility, allowing you to take pictures quickly and easily change the location and shooting angle. But small sensor have much higher noise level.