Education In Motion: Production: Equipment: Digital Camera

Aperture

Also known as iris, aperture is the measurement of how much light is actually entering the camera lens. If you are filming in an environment that does not have much light, you will want to increase the aperture. You will decrease the aperture if you have an abundance of light. Aperture is measured "f-stops". The key word here is "stop". A larger "f-stop" will result in a smaller aperture. In other words, more light is being stopped from entering the camera. Lastly, it should be noted that by increasing the aperture you will decrease the depth of field (see below) as some of the shadow detail is depleted.

Auto Vs. Manual Focus

Manual focus (physical turning of the focus ring in the front of the camera) will almost always produce better results. Auto focus is constant adjustment of focus to maintain constant focus on a central object in the camera's lens as the camera moves. This can result in a image that is blurry a good portion of the time. The time-tested approach to focus in a situation where you know you will have movement, especially zooming and pulling back, is to

Zoom in as far as you intent to for the life of the shot
Turn the focus ring until you have the desired sharpness of image or use
Zoom back out

Note that in step two you can use auto focus instead of manual. After you calibrated the camera for focus, switch to manual focus before zooming back out to "lock the focus".

Depth of Field

This is the percieved spatial relationship of your prinicple subject and objects that surround it. A shallow depth of field often results in a film-like look and is achieved by zooming in, shooting close to the subject, or using a large aperture. Deep depth of field gives the impression that objects are far behind your subject and is achieved by using a wide angle lenses, zooming out, using small aperture, or shooting far away from your subject.

Frames Per Second/Modes

Frame modes refer to how many frames per second are shot. When you watch TV, you are watching NTSC mode which involves 29.97 frames being shown every second. It's not that simple however. NTSC is an interlaced signal which means that each frame has an upper and a lower portion that is read thus you are essentially viewing a 59.94 frame per second signal! Progressive Scan, by comparison, is a non-interlaced signal containing only single frames and can contain 30 or 15 frames per second depending on the video camera. Progessive Scan Mode is used to acheive a more cinematic or film-like look.

Gain

Used as a last resort, increasing Gain can bring more light into the camera in very low lighting situations. Beware that increasing gain may have the side effect of producing grainy visual noise to the footage. Gain is usually set to zero.

Shutter Speed

Shutter Speed comes into play often filming quick motion footage like a soccor game or moving vehicle. How long a frame is exposed in the camera is controlled by the shutter speed where 60 is the normal speed. If you want to capture the movement of a car for instance with blurring use a higher shutter speed. Blur of motion can be an intended effect, a lower shutter speed will produce this.

Timecode

You can think of time code as "timestamping" applied to video footage. As you film, code is added to the footage that breaks down into hours:minutes:seconds:frames and allows for precise editing in video editing software such as Adobe Premiere Pro. Hence, a timecode stamp of 08:34:12:14 would translate as the 14th frame of the 12th second of the 34th minute of the 8th hour of film.

White Balance

White balance effects the camera's perception of what constitutes white in its relationship to the current lighting situation. Proper white balance is important to ensure that colors will look correct in the finished video product. To achieve good white balance, zoom in on a white card in the lighting environment in which you will be filming. Hold the white balance button on your camera until the indicator stops blinking. You must reset white balance whenever lighting changes!

Zoom

Using the zoom control affects the focal length of the camera. Zooming out produces a short focal length or wide angle view where distant objects appear very far away. This is also known as an exaggerated spacial reference. Zooming in does the opposite producing long focal length and a narrow angle or close shot. Here distant objects are magnified resulting in a collapsed spacial reference.