Communication between the photographer and the model in portrait photography is very important. For this reason among others, lenses between 50mm and 135mm are often used, in order to maintain a certain distance from the model. The standard zoom lenses which are often sold together with camera bodies cover this focal length range, and are therefore generally suitable for this type of photography. Sometimes, however, it is necessary in portrait photography to use a large-aperture lens with a larger maximum aperture than is offered with such zoom lenses. It goes without saying that getting the most out of the lenses you already have is a good thing, but the powerful effect afforded by a large-aperture lens is the ne plus ultra of interchangeable lenses in SLR photography.

The first element is the beauty of the blur. The wider the aperture, the shallower the depth of field becomes, increasing the blur in the out-of-focus areas. 85mm lenses, which are often used for portrait photography, can deliver an impressionistic background blur effect since they are much brighter than zoom lenses. Single focal length lenses generally have a brighter maximum aperture than zoom lenses making them ideal for photography using a shallower depth of field. And of course if you want to reduce the blur a bit all you have to do is close the aperture the required amount, which gives large-aperture lenses a broader range of expressiveness.

Canon has a large line-up of large-aperture lenses with outstanding optical characteristics. Not only do they allow you to emphasize the subject with their shallow depth of field, but they also deliver excellent image quality compared to zoom lenses.

The extremely shallow depth of field offered by large-aperture lenses when used at maximum aperture means that you have to be extra careful with focusing. Most USM lenses are equipped with full-time manual focusing, making it possible to make small adjustments to the focus even when in autofocus mode, which can be a great help when you have to get the right focus rapidly in difficult focusing conditions.

Portrait photography is not always done outside on sunny days or in a studio with professional lighting equipment. Often the greatest photo ops come outside at dusk or in a poorly lit interior. And there are many places that don't allow the use of tripods. All of these difficult lighting situations are ideal for IS lenses to show off their capabilities.

No matter how beautiful the model's smile or the location, any hand movement during the shot will ruin the photograph. This type of shaking requires the utmost caution and attention especially when blowing up photographs taken with digital cameras.

Methods for preventing the shaking effect of hand movement include using a flash, high sensitivity film for film cameras, and a high ISO sensitivity setting for digital cameras. However, flashes can destroy the lighting atmosphere of a location, high-sensitivity film is grainy, and a high-sensitivity setting on a digital camera will cause noise to be generated in the resulting image. With an IS lens, not only does handheld photography become possible in these situations, but image quality is maintained because the effects of hand movement can be suppressed even when using low-sensitivity film.

Soft focus is sometimes used when taking portraits of women. This can be done by using either a special soft-focus lens or a soft-focus filter.

Soft-focus filters are inexpensive, but they require care when being used. Many of them achieve the soft focus effect through a clear pattern on the surface of the glass, which can often cause the blurred areas of a photograph to appear splotchy or become too evident and ruin the photographic image. In contrast, specially designed soft-focus lenses deliver a natural, beautiful softening effect that envelops the subject in a soft light, throughout the whole image, and the effect can be adjusted. The EF lens series includes a 135mm soft-focus lens that is easy to use in portrait photography, allowing you to achieve expressive and beautiful soft-focus effects.

Using medium telephoto and super-telephoto lenses allows you to bring a model's face completely into the frame when using a 35mm or digital SLR held horizontally. However, when you want to get that one step closer for a shot with greater impact, an extension tube can be useful. Although using one will cause distant objects to go out of focus, it will reduce the closest focusing distance of the master lens.

Extension tubes are attached between the lens and the camera body and can be used with most EF lenses, including the EF-S series lenses. They come in two types, the EF12 II and EF25 II, with different thicknesses (approximately 12mm and 25mm respectively), and the EF25 II can be used at closer distances. The amount you can get closer depends on the master lens being used.