Light takes an extraordinary journey from the sun to our eyes, and the use of digital imaging technology makes this route more complex. The principles of vision and the way light stimulates our eyes doesn't change, but the capture, storage, and reproduction of the semblance of a scene is an incredible technical and biological achievement. In this video, learn about this journey.
- [Narrator] Our brains do a lot of thinking and calculating before information and understanding reaches consciousness. So much happens before we're consciously aware of it, it defies the analysis of modern science. You can recognize faces you've seen before for only a fraction of a second. Or, quickly learn to forget to detect harmless smells, as any owner of a smelly pet will confirm. Everything we see and hear is pre-interpreted by the brain. Our hearing detects very subtle variations in frequency, amplitude, and phase, and amazingly complex pattern recognition is applied in a tiny fraction of a second for us to understand, not just here, what's happening around us.
When we see, the neurons in the back of our eyes break images down into the separate kinds information, including color, brightness, and various kinds of shapes and angles before the information is sent to the visual cortex. Of course, if we're looking at video footage, the light takes a huge journey. Let's imagine an exterior shot of an object or a person. The sun produces light, which reaches the Earth in about eight minutes. This light bounces off our subject, and some of it goes through a filter over a camera lens, through the lens onto a sensor that counts the number of photons in different areas of the picture.
This photon count is converted into binary, and there's more on this in the lesson about binary. It's often then converted into a color system, so the information can be stored, usually as a smaller file, using compression, and again, more on this in the lesson about video compression. That file is then later decompressed to be viewed. The information travels through a graphics processor, and via the CPU and memory on a computer, it gets displayed on a screen. And the light emitted from the screen reaches your eyes, which perform exactly the same analysis as they would if they saw the subject in person.
It's quite a journey, but the principals of light, shadow, form, and composition, are relatively simple. They haven't changed since the origins of cave painting, and before, because the way our vision works, hasn't changed either.
Get ready to remove the mystery behind terms you've encountered. If you work in a creative profession, this can enhance your command of the tools you use. Learn what a pixel really is, what color channels are, and what audio frequency is. Discover how color channels, bit depth, and video frame rates work. Find out the difference between codecs and file formats, and how compression is involved. By the end of this course, you'll know how to answer common client questions—like, whether a logo should be supplied in vector or bitmap form, and more.
Note: Motion graphics in this course were provided by Chelsea Parrish: chelseaparrish.com.
- What is a pixel?
- Aspect ratios
- Bit depth
- Alpha and transparency
- Light and color channels
- Color modes: RGB, YUV, CMYK
- Camera depth of field
- Chroma Key and Luma Key
- Blend modes
- Color wheels, vectorscopes, and waveforms
- Video compression and codecs
- Frame rates and timecode
- File formats
- Audio amplitude
- Capturing audio tone as frequency
- Audio timing using the phase