So how are we doing? Are you excited about the new control that you have over your cameras? I really hope that you are enjoying the Tuesday Tips. If you have any questions, please send them my way. I would love to do a post answering all of your questions.
OK, my friends, let's get right to it. So you want to know how to choose your focus.
First, let me be clear... we are not going to manually focus the camera. We are keeping the camera in Auto Focus (AF). We are just simply telling it where to focus. Let me show you...
It is important to tell your camera where to focus. Left to it's own devices, the camera will choose an area in the scene with the most contrast to focus on. It may or may not choose the right area to focus on. Chances are, it's going to miss focus. So you need to tell it where to focus. When taking photos of people, it's usually best to focus on the eye. You want the eyes to be the sharpest area of focus in the image. This is true for kids and real, live puppies...
You can also use the focal points to get a little creative. This helps when you are trying to tell a story with your images...
A word about aperture...
When you choose a wide aperture (remember that's the small number), you will have a small Depth of Field (DOF). The Depth of Field also called focus range or effective focus range, is the distance between the nearest and farthest objects in a scene that appear acceptably sharp in an image. At f/1.4 you only have a tiny sliver as your DOF, the rest of the image will be blurred.
ISO 400 f/1.4 1/320 sec. Tiny sliver of focus is right on Mr. Butterfly's eye and the upper part of his wing.
When you choose a narrow aperture (the larger number), you will have a greater Depth of Field (DOF). At f/8, more of your image will be in focus. Your plane of focus increases.
You may want to increase your aperture if you have many people in the image. If they are not all on the same plane, increasing the aperture allows you to keep all of the subjects in focus. My trick is keeping their eyes as close to the same plane as possible, and also increasing the aperture to about f/2.8. Imagine that there is a plane of glass in front of them. If their eyes are all on this same plane, it is possible to get everyone in focus at f/1.8. For multiple people, I usually place my focal point on one person's eye and make sure that all of their eyes are as close to the same plane as possible.
ISO 400 f/1.6 1/320 sec. If I put a piece of glass in front of their faces they are all on the same plane.
ISO 200 f/2.5 1/1000 sec. Not quite the same plane here, so I increased aperture a bit to be sure to get them in focus.
ISO 2500 f/2.8 1/125 sec. Here we are not on the same plane so I increased aperture to f/2.8.
For landscape images, you generally want to use a narrow aperture. This allows you to get more of the scene in focus. To achieve the maximum depth of field (DOF) in landscape images there is something called a hyperfocal distance. Hyperfocal distance is the point where, if the focal point is focused at that distance, everything from half that distance to infinity will be in focus. Now that sounds really complicated and there is a mathematical method to calculating it. But generally, if you focus 1/3 the way up from the bottom of the scene you will be close enough.
ISO 100 f/14 1/150 sec.
Wow... so far we've tackled the exposure triangle, we learned to shoot in manual mode and we learned how to choose focal points. Amazing isn't it? Surely that's it, right? No... there is SO MUCH more. Next we will look at lenses.
As always, please feel free to email me your questions. See you next Tuesday!