Vernier Tech Info Library TIL #1924

Question

Which digital video camera should I purchase for video analysis?

Answer

1) Digital Video (DV) Cameras - It is difficult for us to recommend cameras because the manufacturers are continually updating their product lines. For video analysis you need a consumer-grade DV or miniDV camera sold by brand name manufacturers, e.g. Sony, Canon, Panasonic, etc. These cameras typically cost $200 to $300. Get a camera that allows you to manually set the shutter speed to least 1/500 second. Some cameras are too automatic and don't allow you to set the shutter speed. You need to set the shutter speed so that fast moving objects aren't blurred on individual frames. If the camera does not allow you to set the shutter speed, look at a camera that has a "sports" mode. That mode has a fast shutter speed. It is also helpful to have a camera that has manual focus capabilities.

There are two common ways to transfer video to your computer: video stream, and as a file. If you use streaming video, the camera must have a firewire (aka i.Link) port, or a USB 2.0 port that functions as a video stream source. Firewire is more reliable.

If the camera creates files, they must be Quicktime-compatible. Usually a camera that creates "avi" file or a "mov" file can be used, but only a test will determine compatibility.

Many video cameras on the market have features that do not lend themselves to video work in the classroom. Quite often video cameras that record to optical disk DVD, or that record to MPEG-1 format, or record to a hard drive do not work well in this application. Unfortunately they often use compress series of frames and you lose important detail. This problem can also occur with HD cameras.

2) Still Digital Cameras - Most still digital cameras have a movie mode. These cameras will work, but they have an important limitation. As far as we know these cameras do not allow you to control the shutter speed, which means that moving objects may be blurred in individual frames. Of worthy note is a series of cameras from Casio:
http://www.casio.com/products/Cameras/High_Speed_EXILIM
One of the options with these cameras is the ability is to take hi-speed movies, e.g. 200 to 1200 fps. This is a great option for physics since it allows you to analyze fast motion, e.g. swing of a baseball bat.

Still cameras with movie mode do not stream video, but will create files for transfer to your computer.

3) Important recommendation - It's very important to test a camera with your computer and Logger Pro to be sure that the file format is compatible with Quicktime, and that you can install the necessary drivers for your camera. (This is generally only a concern with Windows.) We do not recommend buying a camera without first testing it or a very similar model.

Created by: rsorensen/jgastineau on December 05 2008
Last updated by: rsorensen on June 19 2009