When shooting a close-up of people’s face, it is highly desirable to have their eyes in sharp focus and at the same time render the background blurry to avoid distractions. This situation typically requires accurate focus and large lens aperture. Here are some tips on how to focus on the eyes.
Focus-and-recompose technique should typically work fairly. On many cameras, the center focus point is the most sensitive and accurate. Therefore it may be the best option to simply focus on the eyes and recompose the frame. Be aware that focus-and-recomposes can have some pitfalls.
If you are concerned about focus accuracy using focus-and-recompose technique, another way is to use a off-center focusing sensor point. Many cameras have multiple focusing sensor points. Choose the one that’s right over the eye when the desired composition is achieved. If no focusing sensor point is exactly over the eyes, just select the one that is nearest to the eyes then do the focus-and-recompose. This will minimize the focusing error. Or you can compose loosely so there is a focus sensor point over the eyes, then crop the photo to desired composition.
Finally, you can always try manual focus if the light is not too dim.
If you still cannot get a good focus on the eyes, you may need to increase the depth of field (DOF) by stopping down the aperture. What may happen then is the shutter speed becomes too slow. In this case, you will need to either increase the ISO or shoot with flash.
Keywords: Depth of field, DOF, Focus, focus and recompose, portrait