When you pick up a camera – whether it’s the one built into your smartphone or an Arri Alexa XT 4K—you are in fact encountering a history of development that spans almost 150 years. Today’s cameras rely on the same basic principles that drove the earliest motion picture systems. As a professional media maker who seeks to be in control of the aesthetic possibilities of the medium you are working in, you will need to understand a complex array of specifications: frame rates, aspect ratios, resolutions, color encoding, sampling and data rates. Each of these has much to do with technological innovations that occurred at various points in the history of the film, and then the video, moving image. Understanding those principles is critical if you are going to make the best use of the technology available to you today, and tomorrow.
High Resolution and Color Figures
The CMOS sensor: individual pixels convert light energy into electronic brightness information at the photodiode (circles) and then amplify that signal (triangles) before reading the charge out to an analogue/digital converter (ADC) (one dedicated to each column). Horizontal pixel rows are read out, from top to bottom, one at a time according to the scanning rate (see also page 217).The resolution can be roughly determined by multiplying the horizontal and vertical pixels. This illustration shows the relative resolution capabilities of ATSC formats based on pixel countJust like camera sensors, color flat-screen displays (LCD or plasma) are made up of millions of pixels. Each individual pixel contains red, green, and blue subpixels (outlined). See the color insert.Comparing the HD standard Rec. 709 color space (inner triangle) with the UHDTV Rec. 2020 color space (outer triangle) reveals the expanded range of colors that the new system can reproduce. See the color insert.A comparison of the relative resolution capabilities between 1080 HD, 2160 UHD, as well as 2K and 4K D-Cinema formats based on pixel count.
