Difficulty: Rating: GCSE Marks:

GCSE Text:
Charlie’s video camera normally records smooth video at a rate of 25 frames per second.

Today though, Charlie is using it in time lapse mode, where one frame is captured every 15 seconds instead. He records in time lapse mode for 2 hours continually.

a) When the time lapse recording is played back at 25 frames per second, how long will the clip last (in seconds)?

b) The camera has the option to play back at a faster 30 frames per second rate. How much shorter will the clip last if it is played back at this faster rate?

Suggestions:
This is a good question to test students’ understanding of worded questions. Normally words like ‘per’ need to be highlighted, and this is easily a non-calculator arithmetic question. Students take 1-2 minutes to answer this question in full.

Teachers could extend the learning by considering:

• The normal frame resolution is 1280 x 720 pixels, but has a full HD option of 1920 x 1080.   How many more pixels are there in a full HD frame than the normal frame?