FAQs
A
4k resolution
Film format with approximately 8 million pixels, in which the number of horizontal pixels is fixed (4 096) and the number of lines results from the picture page format selected during shooting. Theatrical films are often produced with an aspect ratio of 2.35:1 – this results in a line count of 1,743 for 4k. Alternative: UHD (with fixed aspect ratio 16:9).
Resolution
Measure of the detail of an image. Often confused with pixel count in camcorders and cameras. The resolution of camcorders is measured in pixels by width and height. Example: 1 280 x 720 pixels (Full HD).
4k. Film format with approximately 8 million pixels, in which the number of horizontal pixels is fixed (4 096) and the number of lines results from the picture page format selected during shooting. Theatrical films are often produced with an aspect ratio of 2.35:1 – this results in a line count of 1,743 for 4k. Alternative: UHD (with fixed aspect ratio 16:9).
AVCHD
Standard format for videos in high resolution. Stands for Advanced Video Codec High Definition. Video data is stored in MPEG-4 AVC/H.264 format, audio data in Dolby Digital or Linear PCM format. Other common recording formats are: the current HEVC as well as Motion-JPEG and MOV (Quicktime).
AVI
Audio Video Interleave. A file format in which image and sound (audio and video) are transmitted together. This is why experts refer to AVI as a container format. Audio and video data are interleaved. Developed by Microsoft for playing short video clips on the PC.
B
Image chip
The image chip or image converter. Electronic component in action cams and cameras. Converts the image captured by the lens into electrical signals from which a digital image can be calculated. See also CCD and CMOS.
Frame rate
The frame rate indicates how many frames per second are captured by the camera. The technical term for this is frames per second (fps). Action cams today deliver 30 or even 60 frames per second. The frame rate of motion pictures is 24 frames per second. Depending on predisposition and current condition, the human eye already perceives 12 to 16 images per second as flowing movement.
Pixel
A pixel refers to the smallest element of a digital image. Also called pixel.
Image noise
Image noise is a combination of color noise and brightness noise. It is particularly common in low light conditions. Noise can also occur at a high ISO setting.
Image stabilizer
The image stabilizer is an electronically controlled, mechanical or optomechanical component in the lens or camcorder. It works against shaky shots. An optical image stabilizer built into the lens delivers better results, as the shaking movements are already compensated for in the lens before the actual image is created.
Aperture
The aperture is used in photographic lenses to regulate the amount of light entering the lens. The aperture provides the correct exposure and affects the depth of field. In the human eye, for example, the iris also regulates the amount of light that hits the retina. The more light, the smaller the iris becomes.
Focal length
The focal length affects the angle of view of a lens. A normal image impression results, for example, for a 35 mm resolution at 50 millimeters focal length. A shorter focal length provides a wide-angle image, while a longer focal length provides telephoto images.
Byte
Byte is the term used to describe the information and storage unit of digital technology. A byte consists of eight bits. One kilobyte is 1,024 bytes, one megabyte is 1,024 kilobytes, and one gigabyte is 1,024 megabytes.
C
CCD
CCD is an image chip in action cams and digital cameras. The CCD photo sensor converts light into electrical signals. The abbreviation stands for Charge Coupled Device. Translates roughly as charge-coupled component. Advantage: Light sensitive, wide dynamic range. Disadvantage: high power consumption, slow data processing. Alternative: CMOS image chip.
CMOS
Image chip in action cams and digital cameras. The CMOS image sensor converts light into electrical signals. The abbreviation stands for Complementary Metal Oxide Semiconductor. Translated approximately complementary metal-oxide semiconductor. Advantage: saves power, works fast. Disadvantage: strong, unevenly distributed image noise. Alternative: CCD image chip.
Codec
A codec is a program that is needed to encode and decode data. CO- coding DEC – decoding To German: Kodieren und Dekodieren.
The codec determines the resolution, frame rate and compression of a video. The software reduces or compresses the data. This saves storage space. During playback, the software decodes the original data from the compressed data stream. Examples of codec systems: HEVC (Blu-ray Disc), MPEG4 (AVCHD, AVC) and MPEG2 (DVD).
D
Data rate
The data rate indicates the amount of data that the action cam records per second. In the AVCHD standard, this is a maximum of 24 megabits per second (Mbps), with HEVC even several hundred Mbps. The higher the data rate, the more detailed the recording. However, the hardware requirements for the camera are all the greater. A high data rate leads to sometimes very large video files.
Digital zoom
The digital zoom simulates a telephoto effect by enlarging a portion of the image. You can achieve the same effect by cropping when editing images on a PC. The digital zoom degrades the image quality in the cropped image because the image resolution is reduced relative to the original image. A better solution is an optical zoom, which enlarges the section even before the image is generated.
Diopter adjustment
For spectacle wearers, the possibility of individual adjustment of the viewfinder to the photographer’s visual acuity and the possibility of using the viewfinder without glasses.
DisplayPort
Is a particularly powerful video interface for computer monitors. Especially recommended for very fast movements and 4K video editing. Alternatives: HDMI, DVI.
DivX
Stands for Digital Video Express. It is an MPEG-4 compatible video codec. Its strength: It delivers highly compressed video files with nevertheless good quality. Perfect for feature films and long videos.
DVD
DVD is the abbreviation for Digital Versatile Disc. It is a digital storage medium, similar to a CD. However, a DVD can store significantly more data than a CD. Self-recordable DVDs have a storage capacity of 4.7 GB. The DVD is one of the optical data storage media. Successor: Blu-ray Disc.
DVI
DVI stands for – Digital Video Interface. It is an interface for the transmission of digital video data (similar to HDMI, but without sound signal). It is used with computer monitors. Alternative: HDMI, DisplayPort
Dynamics
Dynamic range is the difference between the brightest and darkest image information in video. It should be particularly large for high-quality videos, with evenly graded color and brightness gradients.
E
Exif
Exchangeable Image File Format. Exif is the standard for additional information on digital images – such as the camera used, selected focal length and exposure time, or GPS location information.
F
Color noise
Color noise is defined as empty colored pixels in monochrome areas. Stronger in darker parts of the image and mostly at higher ISO of the camera. It occurs together with brightness noise. See also Image Noise.
Color depth
The color depth defines the maximum number of colors for digital display. From 3 x 8 bits per basic color = 24 bits (16.8 million colors) one speaks of true color representation. The trend in scanners and image processing: 3 x 16 = 48 bits (281 trillion colors) to get even more color information.
Full HD
Full HD is the currently still common resolution of television with 1,920 by 1,080 pixels. In comparison, UHD has four times the number of pixels, but the amount of data that must be transmitted is many times greater than Full HD.
G
Backlight correction
The camera responds to backlighting with automatic backlight compensation and adjusts the exposure accordingly to prevent the subject in the foreground from becoming too dark. Depending on the exposure program, this works more or less well. However, it is often necessary to adjust the exposure time or aperture manually.
Facial recognition
Facial Recognition or Face Detection. The camera analyzes the image during recording. If facial structures are detected, it will preferentially adjust focus and exposure accordingly. This technique can be used to enhance portrait and group shots.
Gigabyte
1GB = 1,024 megabytes (see bytes).
GPS
GPS – Global Positioning System, the camera determines its location via satellite and records it in the Exif data.
H
Field
Former standard of television technology: The camcorder composes the video image from two fields (i for interlaced). More modern is the composition of full frames (p for progressive). Both methods can produce high quality images.
HD
High Definition, high resolution: This abbreviation indicates videos with at least 720 picture lines. Typically 1 280 x 720 and 1 920 x 1 080 pixels are used.
HDMI
High Definition Multimedia Interface. Interface for the transmission of digital audio and video signals.
Brightness noise
The color-neutral portion of the noise in an image. In areas of equal brightness, brighter or darker pixels stand out. The brightness noise only becomes visible when the image is converted to grayscale. Occurs together with color noise. See Image Noise.
Brightness gain
The camera reacts to the available light. It automatically increases the brightness in dark areas.
HEVC
High Efficiency Video Coding, a standard developed for encoding video in 4k resolution. Compresses video data twice as much (half the file size at the same resolution) as the H.264/MPEG-4 standard, which is still often used today, while maintaining the same quality.
I
Interlaced
Transmission of fields. Critical for fast movements. Opposite: progressive (see there).
J
JPEG
Joint Photographic Experts Group. Widely used file format for data-reduced images. Saves memory. However, this is associated with a reduction in image detail and colour fidelity.
K
Compression
Reduction of the amount of data, which, depending on the method, may be accompanied by a loss of detail and color fidelity.
Contrast
Ratio between the brightest and darkest values of an image. If the contrast is low, the picture will appear dull. If it is high, the image looks hard.
L
LCD
Liquid Crystal Display: Liquid crystal display. Screen on action cams and most TVs. A system of glass plates with a layer of liquid crystals between them. These let through a lot or little light depending on the control. The display does not light itself. LEDs behind the display provide the light.
Light sensitivity
Shows how much light the camera needs to take decent pictures. The light sensitivity in lux is often given in data sheets and advertising brochures. The lower the value in lux, the less light the camcorder needs.
Lithium batteries (Li-Ion)
Particularly powerful batteries. Advantage: comparatively small and light. As a polymer battery, it can be adapted to the shape of the housing as required. Disadvantage: Only about 300 charges. Temperature sensitive.
M
Megabyte
1.024 kilobyte (see byte).
Megapixel
Specification of the pixels captured by an image chip. Calculated from the number of pixels (width times height of the image chip – in millions of pixels).
MOV
Quick Time Movie. File format for video files. Developed by Apple.
MPEG
Motion Pictures Experts Group. Standards for compressing video, similar to JPEG compression for photos.
N
Audio dubbing
Subsequent mixing of the audio track with music or sounds. Works on the PC. Video editing programs also offer sound mixing functions.
Normalized focal length
The focal length is specified in relation to the size of the image chip. The value 1 corresponds to the normal field of view. Values below mark the wide-angle range, above the telephoto focal length.
O
Lens
Lens groups that project the image onto the film or an image chip. They are classified according to focal length and image impression (macro, wide-angle, normal, telephoto) or have a variable focal length (zoom).
P
Pixel
An artificial word made up of the terms picture and element. Smallest element of a digital image.
Pixel number
Number of pixels on a given surface, for example on a photochip.
Progressive
Full frame transmission. The image appears sharper and calmer. Opposite: Interlaced (see there).
Proxy Cut
Trick to edit high-resolution videos even on weaker computers by performing all editing steps on data-reduced copies. They are only applied to the high-resolution raw material later.
Q
QuickTime
Video file format developed by Apple that is also compatible with Windows computers.
R
RGB
Red, green, blue – basic colors for additive color mixing, for example, on the monitor and especially in the human eye.
S
Storyboard
Timeline in the video editing program. Shows the scenes in chronological order. Good for the overview when cutting.
SDHC
Memory card format and default definition. SDHC stands for Secure Digital High Capacity.
Viewfinder
A device on the camera that allows you to focus on a subject and compose the picture.
T
Timeline
Scene window in the video editing program. Plots video, audio, and effects tracks on a timeline. Good for video editing and dubbing.
U
UHD
Ultra High Definition. A television format with a fixed aspect ratio (approximately 16:9) and 2 160 by 3 820 pixels. Theatrical films in the common 2.35:1 aspect ratio have 1 625 lines in UHD (and a black BAlken above and below the film). Alternative: “4k”, which is often mistakenly used as a synonym for UHD.
USB
Universal Serial Bus. Interface for connecting additional devices such as digital cameras and printers to the computer.
V
Distortion
Lens image errors. Straight lines are displayed curved at the edge of the image. A rectangle is distorted in a barrel or pillow shape.
Full screen
The camera composes the video from whole frames (p for progressive). Up to now, the usual method for television technology has been the composition of two fields that result in a full frame (i for interlaced). Both methods can produce high quality images.
W
White balance
Tuning the camera to the color temperature of a lighting: such as daylight or tungsten light. White balance is the process by which the camcorder learns what shade of white a person perceives as white in that lighting condition. The setting controls the color balance of the images. It decides on exact colour reproduction or artistic alienation.
X
Xvid
A free MPEG-4 video codec. The most popular MPEG-4 codec besides DivX and Nero Digital. Delivers highly compressed video files with good quality. Perfect for feature films and long videos. Xvid is based on the DivX standard.
Y
YouTube
Online portal for video clips. Users can watch and upload video clips for free.
Z
Zoom
Lens with variable focal length.
Zoom factor
Ratio between the longest and shortest focal length of a zoom lens.
