I reckon a good knowledge of photography (and experience) helps to obtain better results. Knowing `depth of field' can give only the main subject in sharp focus

I reckon a good knowledge of photography (and experience) helps to obtain better results. Knowing `depth of field' can give only the main subject in sharp focus. Examining the background and/or resting the camera on/against physical object before taking the snap could achieve a better result. The quality of the lens system in the `camera' is also very important!