If the number of scan lines per frame is increased, what happens to frame rate?

• A. Frame rate decreases
• B. Frame rate increases
• C. Frame rate unaffected
• D. Frame rate cycles

Answer: (A)

Increasing the number of scan lines per frame means more data must be collected for each frame, which takes more time. Since frame rate is how many frames are produced each second, longer frame times lead to fewer frames per second. In other words, frame rate is inversely related to the time required to acquire one frame, so adding scan lines reduces how often you can refresh the image. This comes with a trade-off: more scan lines can improve lateral (spatial) resolution, but at the cost of temporal resolution.