http://www.adorama.com/alc/taginfo/shell <p><span style="font-size: small;">If you've ever seen lighting in a pro studio, you'll have noticed that thelight sources are large, with either the flash being bounced from an umbrella or inside alarge softbox. The reason for this is that the larger the light source, the softer yourshadows will be.</span></p> http://www.adorama.com/alc/article/8363