A light with a large, diffused surface area will produce a soft light for a studio or production environment. The largest surface area, will produce the softest light, the greatest "wrap around" feel, and the least shadow definition. A Chimera Lightbank will convert almost all hard lights into soft lights. Good dedicated soft sources include Lowel Rifa and Caselites, as well as most good size fluorescent sources such as Kino Flo Divas. Inverting a hard light into an umbrella or reflector will also produce a good soft light, inexpensively. Consider the spill, and practical issues of size.