Vimeo video sharing service has put together a sweet three part video series of lessons called Behind the Glass. It covers introduction to shooting with DSLR cameras fixating on lenses, focal length and depth of field with Vincent LaForet and Blake Whitman.
Vimeo: A camera without a lens is like macaroni without cheese, a ship without sails, Simon without Garfunkel... you get the point. Your lens is an important, multitasking gadget, allowing you full control over a variety of aspects to your shot. Aperture, focus, and focal length are all dictated by this handy device. But don't take our word for it! Camera guru, Vincent LaForet is here with Blake to show us the basics on what lenses do and how to pick one that is best for your project.
Behind the Glass Part 1 - Introduction to Lenses: Full Article
Behind the Glass Part 2 - Focal Length: Full Article
Behind the Glass Part 3 - Depth of Field: Full Article
More Lessons: Visit Vimeo Video School