A quick Beginner's Tip for shooting with shallow depth of field.......
Shooting portraits with a fast (wide-aperture) lens creates those soft, dreamy backgrounds that everybody loves. But this very shallow depth of field can make it challenging to keep our subject in sharp focus.
Focus your focus point on the nearest eye.
The above photo was shot with my Fast Fifty lens from about 4 feet away, at an aperture setting of f2.5. This, according to my trusty iPhone depth of field calculator app, gives me a total depth of field of about 2 &1/4 inches. That's only 2 1/4 inches of sharp focus! Anything in front of that thin plane of focus, and anything behind it, will begin to look soft. This is why it is so important to put your focus point right where you want it.
It's all about the eyes! Generally it's not overly important to see ears and mouths and noses in sharp focus. But the eyes must be sharp... or I should say, the nearest eye must be sharp. Therefore, that is where we want to put our focus point.
You wouldn't dare blur these eyes..
To do this- Set your camera to utilize only one focus point, the one in the center. (it's easy to do...you have read your manual right?) Now when you prepare to take your shot, just put the center focus point right over the nearest eyeball and depress the shutter button half-way. When you hear the "beep", the focus is locked on. Now, if you don't want that eye directly in the middle of the photo, keep holding the button half-way while you recompose the shot, and then click. Be careful when recomposing that you don't lean forward or back. Just a little movement can throw off your focus- remember we only have 2 1/4 inches in this example.
If you are shooting very close up, or using a lens with a crazy fast aperture like f1.2, you may have a total depth of field of less than one inch! In this case you should not even dare to recompose the shot, just focus and click- you can adjust the composition in post processing.
Keep in mind, if your subject is moving, wiggling, jumping, twirling, or bouncing, you're not going to have much luck nailing your focus. Crank the aperture down to f8 and your depth of field will become much much deeper, making everything look sharp.
Hope you like,
photo jabber blog by tim wyler
simple tips and techniques for beginner photographers
depth of field for portraits