Could someone please tell me where to focus when taking a portrait picture of a couple who are standing next to each other. Thank You
If you are using a wide aperture thus having a shallow depth of field it is best to focus on the eyes of the person closest to the camera(even if they are in the same plane, one of them will still be eventually a little closer). This is because viewers usually concentrate on the subject that is in front.
If you use a narrow aperture such as 8 or 9 you should still focus on the closer person but it will not make such a great difference.