Camera and lens
A camera records moving pictures. The lens collects light and decides how much of the scene fits in the picture. When you zoom in, the lens sees a narrow part, so things look bigger and closer. When you zoom out, it sees a wide part.
Three settings matter most. Resolution is how many tiny dots (pixels) make the picture; more dots give a sharper picture and a bigger file. Frame rate is how many pictures are shown in one second (fps). Films often use 24 fps; many videos use 25 or 30 fps. Focus makes the main thing sharp, not blurry.
Always check the battery and the memory card before you start. A flat battery or a full card ends the shoot.
Keeping the camera steady: tripod and other supports
Hands shake a little. On screen, that small shake looks big. A tripod is a stand with three legs that holds the camera still. Its head can turn left and right (a pan) or up and down (a tilt) smoothly.
A gimbal is a hand-held support with small motors that cancel shake while you walk. If you have no tool, hold the camera with two hands, keep your elbows close to your body, or rest it on a wall or a table.
Light: seeing is possible only with light
A camera needs light. Too little light gives a dark, grainy picture. Too much gives a washed-out white picture. This balance is called exposure.
Simple tools: a lamp or the sun as the main light; a reflector (a white card or foil board) that bounces light into dark shadows; a diffuser (thin cloth) that makes harsh light soft. Put the main light on the side of the face and in front, not behind. A bright window behind a person makes them look like a dark shape.
Light also has a colour. Warm light is yellow; cool light is blue. The camera setting white balance tells the camera what white looks like, so colours stay true.
Sound: the microphone
Half of a video is sound. People forgive a slightly poor picture, but not bad sound. A microphone changes sound waves into an electric signal that the camera can record.
The golden rule: keep the microphone close to the speaker. Sound gets weak very fast as the distance grows, and room noise then seems louder. A lapel mic clips on a collar. A shotgun mic points at the speaker from just outside the picture. A windshield (a fluffy cover) cuts wind noise. Wear headphones while recording to hear problems at once.
Materials, storage and care
The "materials" of moving images are not paint or clay. They are memory cards, cables, batteries, hard drives and software. Use a fast, empty memory card. Keep spare batteries charged. After a shoot, copy the files to a computer and to a second drive: this is a backup. Edit a copy, never the only original.
Safety and care: do not leave cables where people can trip; keep lamps away from cloth and paper because they get hot; keep gear dry and clean the lens only with a soft cloth; ask people before you film them.
Try it: a three-minute check
Use a phone. 1) Put it on books so it cannot move. 2) Face a window and record 10 seconds. 3) Turn your back to the window and record 10 seconds. 4) Speak from 3 steps away, then from 1 step away. Watch all clips with headphones. Write which one was best, and why. In the 3D above, do the same with the sliders and the tripod box.
Key formulas and definitions
- Key idea: steady + light + sound
- Frame rate: 24, 25 or 30 fps = pictures shown every second
- Zoom in = narrow view; zoom out = wide view
- Mic distance: half the distance gives much louder, clearer voice
- Backup rule: keep your files in 2 places
Worked examples
1. A video of a student at a window looks like a black shape. What is wrong and how do you fix it?
The window is behind the student, so the camera sets itself for the bright window and the face goes dark. Turn the student to face the window, or switch on a lamp in front, so the face gets the light.
2. You record an interview in a market. The voice is very faint and the crowd is loud. Name two fixes.
Keep the microphone close to the speaker (a lapel mic or a mic held just out of the picture), and put on headphones while recording. If you can, move to a quieter corner.
3. A walking shot is jumpy. Which tool helps and why?
A gimbal. Its small motors cancel the shake of your steps. With no gimbal, bend your knees, hold with two hands and walk slowly.
4. A film clip runs at 24 fps for 10 seconds. How many pictures are in the clip?
24 pictures every second for 10 seconds: 24 × 10 = 240 pictures.
5. A memory card has 64 GB free. One minute of your video takes about 400 MB. About how many minutes fit? (1 GB = 1000 MB)
64 GB = 64,000 MB. 64,000 / 400 = 160 minutes.
6. Plan a safe, simple kit for a two-person talk video with a phone.
A phone on a small tripod, a lamp or window in front of the speakers, a clip-on mic for each, headphones, a charged battery, enough space on the phone, and a copy of the files to a computer after the shoot.
Common mistakes
- Holding the camera in hands for a long shot, then wondering why the video shakes. Use a tripod or a firm rest.
- Standing with the sun or a window behind the person. The face turns dark. Put the light in front.
- Putting the microphone far away and fixing the sound later. Bad sound is very hard to repair, so record it close.
- Not checking the battery, card space and a test clip, and losing the shoot. Also, keeping only one copy of the files.