When you look through your camera viewfinder, you see multiple focus points. When you half press your camera’s shutter button, some of these focus points will light up to lock onto the subject being captured.
The number of possible autofocus points depends on the camera. Some DSLR’s have a 9 point system, while other cameras have 11 point or even 51 points.
I use a 9 point system camera which isn’t a lot. Don’t get me wrong, it’s really nice to have a sophisticated Autofocus system but not absolutely necessary. When there are a lot of focus points scattered through the viewfinder, It’s easier for the camera to keep the object you are tracking in focus.
So the bottom line is that more focus points are better. Even the most basic DSLR now comes with 9 points AF system.
Your camera also comes with metering modes to determine the correct exposure depending on the amount of light that goes into the camera. These metering modes works along with your camera’s focus points as well.
The most common metering modes in DSLR’s today are:
Evaluates light around a selected focus point and ignores everything. I personally use this mode a lot in my bird photography as they mostly occupy a small area on the frame. Because the light is evaluated where I place my focus point, I could get an accurate exposure on the bird.
Centre Weighted Metering
This metering does not look at the selected focus points and only evaluates the light in middle of frame. I use Centre Weighted Metering for close-up portraits and relatively large subjects that are in the middle of the frame.
Evaluative in Canon and Matrix Metering in Nikon is the default metering mode on most DSLR’s. One of the key factors that affects this mode is where the camera focus point is set to. It reads information from the entire frame and then prioritize the area around your selected focus point. I use this mode for most of my photography since it does a pretty good job at deterring the correct exposure.
You can greatly improve the composition of your shots by selecting the right focus points and metering mode.
It’s quite easy to compose a good shot with 51 point AF system than using a camera with only 9 focus points. This is how both AF point systems looks like side by side.
I personally use a Canon 60D which only has 9 Focus Points. For most of my photography, I use Evaluating metering mode and only the centre focus point activated.
To compose a shot, I first place my centre focus point on the subject I want the focus on and press the shutter release half-way down to lock focus. I then move my camera to compose the shot and press the shutter button completely to capture it.
This is my usual workflow when working with a 9 point AF system camera.
When you have 51 focus points scattered through your viewfinder, covering all the major areas from left to right and top to bottom, you can straightaway compose your shot and move one or more focus points onto the area you want the focus on.
Hit the shutter button and it’s done…
Camera manufactures are now adding more and more focus points and Canon EOS R is a great example with a total of 5,655 manually selected AF points covering 100% of the frame from top to bottom and 88% horizontally.
Such high number of focus points allow you to establish focus on your desired spot with pinpoint accuracy.
Composition in photography is not always about the perspective or the rule of thirds. It’s a process, carried out carefully by combining creative and technical skills together.
A good eye in photography is all about selecting the right area to focus on, selected the right focus points and how to evaluate exposure around them.