Graphics – pixels, dpi, color depth

Since we spend a lot of time staring at monitors and printouts, what they actually are is important. Let's start by talking about your monitor:

First step - how many little dots of light are shown on-screen. Each of these dots is called a pixel. Older monitors can't display much:

• CGA (320 X 180)
• EGA (640 X 350)
• VGA (640 X 480)
• SVGA (800 X 600 and larger). Everything you would purchase these days falls into this category.

These days, you have many options. See https://en.wikipedia.org/wiki/Display_resolution for more info about this. Most standard sized monitors these days (2018) are running somewhere around 2000x1000. Pity those uf us that started this game in CGA.

Second step - color. Or color depth. Or Bit depth. Basically, thenumber of bits used to indicate the color of a single pixel (https://en.wikipedia.org/wiki/Color_depth )

• 8 bit color. Only 256 different colors. Just fine for text, but photos don't look very good. You can set your system to this, but any newer system can handle far better.
• 16 bit color (called 'high color' on my system). About 65000 different colors. This is really plenty - your eyes can't resolve better than this. Uses two bytes (16 bits) to describe each color
• 24 bit color (called 'true color'). Uses 3 bytes (24 bits) to represent color. Around 16 million colors (16,777,216 to be exact).
• You can even get 30/36/48 bit color. Why? It just makes your video card work much harder for no apparent improvement.

Third step: DPI (dots per inch). Another way to think about this is pixels per inch.

Time for a little math. The viewing area of my monitor is 13" across. I'm running it at 1024x768. So: 1024/13= 78.77. Or, effectively, 79dpi. Not super high, but good enough.