Learning how to control depth of field with your camera isn’t too difficult, but do you know the science behind how it works? This uber-educational 20-minute video lesson gives a thorough explanation of depth of field and the different factors that affect it. It was made by artist Justin Snodgrass, and is also available for download (and in parts) over on his website.
I get a quick time error ;-( Seems like an excellent subject though.
Marja, the solution to most of such problems for that is to use the VLC, which can be downloaded on:
It plays pretty much anything