Sharpness of focus is usually a virtue in photography--but not always. Thanks to technology, some modern lenses are just too sharp for shooting flattering portraits.
For shooting pictures of the less-than-perfect, then, a discussion of how to make your pictures less sharp is in order.
There are many ways of softening images, and not everyone agrees on which method is best. The most popular, however, is to use a soft-focus or diffusion filter.
Lighting is also important. Try using light of a softer nature. If you're shooting outside, turn your subject away from the sun and use a reflector or strobe to fill in the shadow areas. If you're taking the picture indoors and using a strobe, try to soften the picture by firing the strobe into an umbrella or through a diffusion screen or sheet. You'll want to move another reflector close to fill in those unwanted shadows.
Picking a method of filter diffusion will probably depend on how much you plan to spend. A good place to start the comparisons is with the West German-produced Carl Zeiss Softar diffusion filters, the most widely recognized in the field. These run around $75.
"I don't know of any filter that will do what the Carl Zeiss Softar filter will do," says Woody Blackburn, a photography teacher and salesman at Cal's Camera in Costa Mesa. "It will smooth out the skin without having it be out of focus. Many prominent studio photographers use them with their Hasselblad cameras.
"To make the filters, they take optically pure Carl Zeiss glass and put perfectly spaced optical bubbles in it. When you look through it, you don't really see the end result, but it disperses the light through it onto the film in a certain degree, just enough to soften the skin."
Softar filters come in 55- and 67-millimeter sizes, so you may need a step-down ring to adapt it to your lens.
An excellent alternative for the budget-minded photographer would be a Hoya Softner filter, which looks and works much like a Zeiss Softar. Hoyas cost about $25 each, depending on filter size. They come in two grades of diffusion and are made in most of the popular filter sizes, so no step-down ring is needed.
Also in this price range are the Tiffen Softnet filters, which will produce an effect similar to what you would get with a nylon stocking or screen mesh in front of the lens. The nets, sandwiched between two layers of glass, come in several colors and with different size holes. The finer the net, the more diffusion.
Still less expensive are the etched plastic filters made by Cokin, which are priced around $12. This kind of filter may give you a soft look with a loss of sharpness. As you look through it, you can see what the final product will look like. These do not have screw-in mounts, so you'll need an adapter to hold them in place.
Cheaper yet is to use a foreign substance with a clear skylight or UV (ultra-violet correction) filter. The list of these substances is endless: hair spray, petroleum jelly salt, sugar, even dirt or finger prints. Using any foreign substance means you'll get less predictable results. If, however, you're looking for a very foggy effect, you can expect to get that with petroleum jelly or hair spray.
The simplest method is to take clear plastic food wrapping or a sheet of plastic from a clear bag and hold it to the lens with a rubber band. It's quick, and it can be quite effective.
Renting filters is probably the best choice for someone who is not familiar with how diffusion works. The Zeiss, Hoya and Tiffen filters are available to rent at the Pro Photo Connection in Irvine for $2.50 a day.