What is Camera Aperture ?
Understanding the camera aperture is the key for anyone who wants to take better pictures and take their camera out of automatic mode.
The aperture is one of the three components of photography to be considered when exposing a picture, the other two being shutter speed and ISO sensitivity.
It is the one that allows the light to pass through your lens.
In this article, I will help you not only understand openness and how to control it, but also learn more about the creative aspects it brings so that you can create beautiful images.
Camera aperture : how does it work?
The diaphragm is a mechanism inside your lens through which light passes and is directed to the camera sensor.
This is composed of several slats that open or close at the time of shutter release at the aperture value indicated on the camera screen (expressed as a number /f), allowing more or less light to pass through depending on the value selected.
It’s an easy concept to understand if you just think about how your eyes work.
When you move from a bright to a dark environment or vice versa, the iris of your eyes dilates or shrinks, controlling the size of your pupil.
In photography, the “pupil” of your lens is called the aperture and corresponds to the diameter of the diaphragm of your lens.
You can reduce or enlarge the aperture size to allow more or less light to reach your camera’s sensor.
The larger the aperture of your lens (the smaller the number), the more light the diaphragm lets through, it is said to be open.
Example: An open diaphragm at F/1.4 lets more light through than at F/8.
The smaller the aperture (the larger the number), the less light the diaphragm allows through, it is said that it is is closed.
Example: A diaphragm closed at F/8 lets less light through than at F/1.4.
Keep in mind that the change from one value to the other doubles or halves the amount of incoming light.
Aperture priority mode
Also known as aperture priority, this mode allows you to choose an aperture value to control the amount of light coming onto the sensor and thus manage the sharpness area.
In most cases, to use the aperture priority mode, simply select an A or AV mode button and turn a dial to change the aperture value.
I’ll leave you to look in your camera manual for that.
When using the AV mode, depending on the selected aperture, the shutter speed will automatically change according to the available light to obtain the correct exposure.
Playing with the aperture of the diaphragm allows you to be creative with the depth of field.
It is this which allows to obtain a background blur, often used to make a portrait.
For this, you will have to choose a large diaphragm opening.
A small iris aperture, on the other hand, is intended to increase the depth of field, i.e. the area of sharpness.
This is a preferred setting when you want to photograph landscapes, for example.
I recommend using aperture priority mode for subjects with little movement.
Shutter speed priority mode is reserved for moving subjects.
When you choose to work with small aperture stops, be sure to take a look at the shutter speed.
It must not be too slow, otherwise it will cause a blur of movement.
To avoid this, I strongly recommend that you use a tripod or monopod.
The opening priority mode is defined under different names depending on the brand.
- At Canon, this mode is called Av
- At Pentax, this mode is called Av
- At Nikon, this mode is called A
- At Sony, this mode is called A
- At Olympus, this mode is called A
- At Panasonic, this mode is called A
Av: meaning Aperture Value
A: stands for Aperture.
Diaphragm aperture and its relationship to depth of field As we have just seen, the aperture of the diaphragm you choose on the camera has an impact on the depth of field.
The larger the aperture, or if you prefer, the smaller the number, the smaller the area of sharpness in the image will be.
For a portrait, if you want to get a blurred background while having a completely sharp face, you should choose a large aperture, for example F/4.
The smaller the aperture of the diaphragm, or if you prefer, the larger the number, the greater the area of sharpness in the image.
When you want to photograph a landscape, you want the whole picture to be in focus, from the foreground to infinity.
In this case, you should choose a smaller value, such as F/8, to increase the depth of field.
This picture taken at a large aperture limits the area of sharpness.
A second shot with a small aperture of the diaphragm gives a large depth of field.
Now that you have understood the principle, all you have to do is take your camera and test on various subjects by varying the aperture of the diaphragm.