Donald Smith sent in the following explanation of DPI and I thought it would be something you might want to read.
Computers use square pixels to represent images, while video uses rectangular pixels. And this difference drives all of us nuts. This article describes pixel aspect ratio and helps you get your images looking great.
This detailed analysis looks at how to create graphics on your computer that look “right” on FCP. It’s a detailed look at the difference between square and non-square pixels.
Creating keys on the computer is easy – and they look great. Where problems occur is when those specials effects are shot with interlaced video and displayed on an interlaced TV set or monitor. This article describes how to avoid suddenly discovering that all your effects look out of focus.
Confused about what size to create your images? This article explains what image size to use so they import correctly into Final Cut Pro HD.
This is a comprehensive look at how computer and video graphics are different and what you need to know to create great looking video text and graphics. This article can make your life a LOT easier!
HDV uses rectangular pixels to represent its image. Each pixel is short and fat, which means it only needs 1440 pixels to represent an entire line of HD video. However, the computer (and some other video formats) use square pixels to represent the image. So, when you export from HDV to a QuickTime movie, Final Cut converts the pixels from rectangles to squares.
One of the most complex steps in video editing is getting your computer-based images to look good in video. This article explains how video images are different from computer images and what you need to do to make them look great.