2.3 Camera operation

Traditional ‘still’ photography and filming are closely related. The main difference is that, here in Europe, film cameras take 25 pictures or ‘frames’ per second (this standard is known as PAL. In the USA the standard is NTSC which is 29.7 frames per second – often rounded up to 30 frames per second). These photographs, shown one after another at that rate give the viewer the impression of movement. Anyone who is knowledgeable about still photography, therefore, will soon find him/herself at home with a video camera.

When an image is clear and sharp it is said to be ‘in focus’. Unless a camera operator is trying to achieve a certain artistic effect, he or she is normally preoccupied with trying to capture these clear, well-focused images.

The key element that we work with to achieve this is light. Later we will discuss how to light the scene but for the camera operator the main consideration in terms of light is how much of it is getting into the lens to expose the images. The camera’s exposure to the available light is controlled, mainly, with two settings – shutter speed and aperture. In a camera lens there is a screen or shutter that stops light getting in when you are not filming.  When you press the button to record or, in the case of still cameras, take a picture the shutter opens to let light in. The shutter speed setting tells the camera how long to leave the shutter open while the aperture setting, meanwhile, tells the camera how wide to open the shutter. To give us an acceptable image a certain amount of light needs to be let in for correct exposure. If too much light is let in our image will be overexposed – too bright - and with too little it will be underexposed – too dark. Achieving correct exposure, therefore, is striking a balance between the amount of time the shutter stays open and how wide it opens – shutter speed and aperture. It may be useful to think of it all in terms of the following:

Imagine your image as a bucket, aperture as a tap, shutter speed as time and light as water. You need to fill the bucket. You have two choices. You can turn the tap on full (open your aperture) for a short amount of time (fast shutter speed) or you can partially open the tap (close your aperture) for a longer amount of time (slow shutter speed).

Depth of field

Once you’ve understood this basic concept we need to introduce a third factor – depth of field. The ‘field’, in this case, is the camera’s field of vision – everything that can be seen through the camera lens. ‘Depth’ is the distance from the camera lens to the horizon. ‘Depth of field’ is the section of that distance which is in sharp focus. This is controlled with your camera’s aperture setting and is often represented by the letters Av. It is measured in ‘f-stop’ numbers: for example f/2.8, f/3.4, f/4.0, f/4.5, f/5.0, f/5.6, f/6.3, f/7.1, f/8.0, f/9.0, f/10, f/11, f/13, f/14, f/16.

It’s easy to think that the lower aperture numbers represent the shutter opening less and that the higher numbers represent it opening more. In fact it’s the other way around. If you think of these numbers as fractions, by placing a ‘1’ over them, it may be easier to remember. 1/2 is bigger than 1/4 which, in turn, is bigger than 1/10 so f/2.8 opens the shutter wider than f/16. The importance of this is that the lower your f-stop (aperture) number the shallower your depth of field. In other words, if your aperture is set to f/16 pretty much everything in your field of vision – from the camera lens to the horizon – will be in focus. If, however, your aperture is set at f/2.8 your depth of field is very shallow so only the object or objects you are focused on will be in sharp focus and anything nearer to the camera or further away from the camera in your field of vision will be out of focus (blurred).

This is a very useful tool for the film maker. In a cluttered scene you can make sure that the audience is concentrating on the thing you want them to concentrate on by using shallow depth of field to ensure that only that thing is in focus. An advanced use of this shallow depth of field is a method called ‘focus pulling’. This is when the attention of the audience is brought to one person or object in a scene by use of shallow depth of field and then switched to another person or object by switching the focus. The new person or object becomes the only part of the scene that is in focus because the shallow depth of field shifts from the first object to the second.

Remember that we must strike a balance between aperture and shutter speed. . Generally the slowest shutter speed we can use to ‘freeze’ the action (get a clear image that has not blurred because parts of the scene moved while the shutter was open) is ‘60’ which represents 1/60th of a second.  Shutter speed, on a camera, is usually represented by the letters ‘Tv’. The higher the number on your shutter speed dial, the faster the shutter will open and close. If you are trying to achieve shallow depth of field, therefore, you will be opening the aperture wide to let a lot of light in. Therefore, unless there is not much available light, you will be working with a fast shutter speed. In low light conditions a camera operator is often forced to open the aperture wide and use a slow shutter speed to maximize the amount of light getting into the lens. When shooting with a shallow depth of field it is very important that the camera operator ensures that the part of the scene that needs to be in focus is in focus. On the small screens of modern digital cameras this can often be difficult to ensure.


The ‘frame’, in filming refers to the four sides of the image you are shooting – as in a picture frame. When we talk about ‘framing’, therefore, we are referring to the process of deciding what to include in the picture or, as we say, the composition of the shot. The most common mistake of the amateur photographer or videographer is to put the main object or person in the scene in the middle of the frame. However, this is exactly what you should avoid. One of the first rules of picture composition is the ‘rule of thirds’. If you split the picture into three sections across and three sections down you get a grid of nine boxes. These lines – and especially the points where the lines intersect – are the key areas to which the viewer’s gaze is drawn. It is at these points, therefore, that we place the objects of interest to ensure good composition. Also, if you are filming a person who is looking from left to right in your shot then they should be kept to the left of the frame so that they have some space within the shot to look into. See diagram for examples of good and bad framing.

White balancing

Colours show up differently under different light conditions. In order to keep the images consistent, the camera must be ‘white balanced’ before you film every time the light conditions change.

If somebody phoned you and said: “How do I get from here to your house?”, the first question you would probably ask them is: “Where are you?”. Without that information you wouldn’t know how to begin to direct them. In the same way a digital camera uses white to figure out the colour of everything else in your scene.  You simply point the camera at a flat, white object – such as a piece of white paper, and press the white balancing button. This is telling the camera: “this is white”. From that piece of information it can calibrate everything else. This process is called ‘white balancing’. Modern digital cameras often have an automatic white balancing feature that usually delivers an acceptable degree of accuracy.

Panning and tilting

The head of a video tripod is designed to move smoothly to ensure that the camera operator can achieve smooth shots while moving the camera. Moving the camera from side to side is known as panning while moving the camera up or down is known as tilting.


One of the mistakes which amateur film makers make is to zoom in or zoom out too often while filming. Professionals do this very rarely and even then it is usually in a situation where they have no choice. For example, in shooting a documentary the subject may move closer to the camera and the camera operator has no choice but to gently zoom out. The zoom function is so that you can decide upon having more or less of the scene in your frame without having to move your camera and tripod backwards or forwards.

Handheld filming

Wherever possible a camera operator should use a tripod or other camera support to ensure a steady shot. Sometimes, however - such as in live action documentary filming where the camera operator has to react quickly to circumstances outside of his or her control – this is not possible and the camera operator has to hold the camera. To ensure that you get the steadiest possible shots in this situation there are a number of things you can do:

  1. If there is a solid object – such as a tree or wall nearby – lean against it to steady your body

  2. Take a deep breath and exhale slowly. This helps to steady your body.

  3. If you have nothing to lean against you will not to be able to prevent yourself from moving. Therefore it is better to move in a controlled way. Let yourself sway gently forward and back so that, although the image moves, it will be a smooth and steady movement.


Safety on set

A film set is a busy and often frantic place. The potential for people to injure themselves is high. As a camera operator you will usually have a tripod with three legs sticking out and both an audio and a power cable trailing from your camera. All of these are tripping hazards. Be sure to draw the cast’s and crews’ attentions to these and any other hazards. Where possible, tape down cables and use tape or cloths to make tripod legs more visible.

Practical Assignment

Shoot the film project demonstrating good framing, correct focus, correct white balancing and understanding of depth of field.