With this tutorial, we will take a software independent look at some of the vital terminology that is required to build a solid foundation for learning some basics of editing images. The purpose of these standalone lessons is not to learn how to use any specific software, but rather to focus on learning fundamental terminology. It is recommended that you are familiar with all of the terminology that is discussed throughout these lessons before starting to follow along with any image editing tutorials.
Introduction and Project Overview <<MUSIC PLAYING>> In this lesson, we will learn about HDRI or high dynamic range images. Any image that you see, whether it's a print advertisement, a television graphic, or a website displayed on your monitor has what's called a dynamic range. Now this range also referred to as the contrast ratio is the range of values between the lightest and darkest parts of an image. Most of the images we encounter have a low dynamic range. These are usually 8-bit images and typically contain three color channels-- red, green, and blue with values from zero to 255 defining each channel. Now although these images give us a limited range of color and value to work with, they're normally adequate because of the limited ability of the medium, whether it's paint or a computer monitor. High dynamic range images normally use 32 bits of data to store our colors and contain much more color information compared to a traditional 8-bit image. Now HDR images are also stored in floating point values, which means instead of having to use whole numbers to define a color or brightness, we can now use a decimal point to define the different shades. So rather than having a value of 155 and the next value being 156, a particular channel in an HDR image may have the value of 155. 2 or even 155. 794. This gives the image much more higher number of possible variations per pixel. Now in the HDR world, it's possible for completely black and white areas of the image to actually have a lot of information not visible to an 8-bit display medium such as your computer monitor. So in order to see all of the data stored in a 32 bit image, we can use the tone mapping features found in many of today's popular image editing applications. Now having this extra information can give an artist a lot of flexibility in pulling detail from the shadows or adjusting the brightness of specific areas of an image. In the 3D world, we can use high dynamic range images to actually light our scenes, creating a much more realistic render. We can also render our final images in a 32-bit format giving a lot of control to the compositor who is putting this image back together. <<MUSIC PLAYING>>