Chapter 8 Flashcards
(35 cards)
1
Q
Three basic forms of communication
A
- Sight
- Sound
- Motion
2
Q
Lens components
A
- The camera needs several lenses called elements to duplicate the complex working of the eye.
- A lens is two prisms joined together.
- If the prisms are joined at their apexes they from a concave lens that converges the light to a single point.
- If joined at the base, they form a convex lens that converges the light to a single point.
3
Q
Focal Length
A
- Distance from the optical center of the primary lens to the point where the light converges on the focal plane.
- Focal length determines the field of view of the lens.
- Short focal length has wide field of view is called wide-angle lens.
- Long focal length has a narrow field of view and is called telephoto lens.
4
Q
Different Types of Lenses
A
- Wide Angle: 4.5mm to 25mm (allows more control)
- Normal: 25mm to 75mm
- Telephoto: 75mm or longer
5
Q
Zoom vs Prime Lens
A
- Advantage of zoom lens over prime lens (fixed lens) is that the focal length can be set at any point with the parameters for that lens.
- Prime lenses are generally of a higher quality than zoom lenses and are used on DSLRs and high-end cameras.
6
Q
Focal Plane
A
• The point at which the light rays that pass through a lens converge and are in focus
7
Q
Depth of Field
A
- The range of acceptable focus in front of and behind the plane of focus
- 3 factors affecting depth of field: Focal length, iris opening, distance from camera.
- As focal length increases, the dept of field decreases
- As the iris is opened up, the depth of field decreases.
- As the lens is focused on objects closer and closer to the camera, the depth of field also decreases.
8
Q
MOD
A
• Minimum Object Distance- The limit of how close a lens can focus.
9
Q
Aspect Ratio
A
• 4:3 (analog), 16:9 (like our normal human way of seeing things)
10
Q
Iris
A
- Overlapping metal leaves or fins that rotate to make the hole smaller or larger. Controls the amount of light passed on to the focal plane.
- F-stops are used to measure the speed of a lens.
- Fast transmits a large amount of light.
- Slow transmits smaller amount of light.
11
Q
Optical Groups of Zoom Lenses
A
- Focusing group- gathers light into a sharp, clear image.
- Variator group- Moves inside the lens to change the image size from wide angle to telephoto.
- Compensator group- Moves with the variator group to keep the image in focus & reduce aberrations caused by the first 2 groups.
- Prime lens group- Focuses the image on the recording surface, such as film or a TV camera chip.
12
Q
Lens Extenders
A
• 2x range extender- doubles the focal length however it is limited in low-light situations.
13
Q
Light Quality Control
A
- Ultraviolet filter- protects the lens from scratches, dirt, etc.
- Hood- Prevents direct light from striking the front element.
- Lens Flares- Circular patterns or reflections in the lens
14
Q
Lens Filters
A
- Color enhancement- change the perceived color of light
- Diffusion- reduce the sharpness and/or contrast of the picture
- Special effects- Do everything from creating multiple images to split screen. Most of these things can be done in post production.
15
Q
Proper Lens Care
A
- Loose dirt or dust can be blown or brushed away with a soft photo brush or an air blower.
- Do not use your shirt, tissue, or mouth.
16
Q
Filter Wheel
A
- The 1st thing and image passes through in a network quality camera.
- Contains basic filters (clear, color correction, and light reduction)
17
Q
CCDS and CMOS
A
- CCDS more expensive, less susceptible to noise in the picture, require more battery power
- CMO (Complementary metal oxide semi conductors)
18
Q
NTSC
A
- National Television Systems Committee- reference system used in the U.S. from 1940s until 2009.
- Used 525 lines of resolution and scanned at 59.85 fields per sec.
19
Q
ATSC
A
- Advanced Television Systems Committee
* 16 x 9, 1080 lines of resolution
20
Q
Camera Functions
A
- Power Switch- Gives power
- Standby- Used when you don’t need to operate it, but want to start up quick.
- Save on- Gives you a pic in the viewfinder, but prevents the VCR’s tape servo motors from coming up to speed.
- On
- Camera bars- Makes the output of the camera either the picture or the color bar generator contained within the camera.
- Gain switch
- White balance, black balance
21
Q
Monitoring Pictures
A
- Viewfinder shows exactly what the recorder sees
* Can show Zebra bars, which appear over parts of the picture to display the exposure level.
22
Q
Shutter Speed
A
- Normal is 1/60 of a sec
- Fast shutter speeds allow for slow-motion pictures & freeze frames, but show a strobe effect when playback at the normal amount of frames per sec
23
Q
Waveform Monitor
A
• Needed to make adjustments on the electronics of a camera.
24
Q
Vector Scope
A
- Checks the color or chroma of the TV signal.
* Ex: If reds don’t look right this will tell whether it’s the operators eye, the TV set, or the camera that is wrong.
25
Type C Format
* One inch tape format became the studio standard for years, but wasn’t practical in the field.
* Had good resolution and allowed special effects like slow motion without distortion.
26
Sonny Betacam
ntroduced in 1982 dominated the professional world of videotape for portable recording.
27
DV
* Developed in the late 1990’s for lower-end professional or industrial market.
* All DV formats use an 8-bit 4:1:1 sampling rate.
28
Flash Memory
* Many camcorders have he ability to record directly to a memory card.
* SD Cards (secure digital)
* CF (compact flash)
* Advantages: Has no moving parts and is not sensitive to extreme temperature, vibration, or shock. Rewritable.
29
Time Code
• Allows each frame of the video to be numbered. When played back scenes or shots can be located by their time code.
30
Troubleshooting Equipment
* Always check battery 1st.
* Tape decks (Is the record tab in place?)
* Know the switches and buttons on equipment
* Head cloggs
31
Proper Battery Care
* Amps = watts/volts
* Ideal temp is 75 degrees
* No leak icepacks help cool camera and battery
32
Tripod Components
* Fluid head- Acts as dampening agent to resist movement so that the camera doesn’t jerk.
* Pan/tilt locks
* Counterbalance
* Tripod legs
* Spreader
33
Dolly
• Forward and back movement of the entire camera unit
34
Crane
• Camera mount that allows it to be raised or lowered
35
Boom
A pole that holds Mic
