Focusing with Macro Photography
Manual focus should be used for true macro photographs 1X to 5X. You might get by with auto focus on close ups, but the closer you get the more manual focusing becomes mandatory.
It is hard to get that much of the object in focus. It is very difficult to get much in focus no matter what equipment is used. Just go with it and give up trying to force the issue! The goal is to situate the camera and the flower so as much of the flower is in focus as possible. The closer the lens gets to the flower, the less there is of it in focus. There is no way around this. Some macro photographs only have a few millimeters of depth in focus! Hardly anything is in focus. The best way to get as much as possible in focus is to keep the focal plane as parallel as possible to the flower. If more of the flower needs to be in focus, then get further away, or use a smaller aperture (explained later in Depth of Field).
The focal plane is the angle of the sensor, and the part of the image that is in focus. It is better to have the sensor (or the back of your camera if it is easier to think of that way) as parallel as possible to the surface area of the flower since focusing is so limited. Some flowers or insects are difficult to photograph really close because too much of it will be out of focus. Pick your angle carefully! Too sharp of an angle will put most of the subject out of the focal plane of focus! Flowers have curves of course, but carefully pick a part of the flower to focus on that is as parallel as possible to your sensor.