Length Lens: However, although a long focal length lens is mandatory, it need not be expensive. The utmost of critical sharpness in a portrait lens is not necessary, or even desired, since considerable diffusion can be tolerated in portrait negatives. Your lens needn't be in a shutter for strictly studio portraits, either. A lens in barrel is perfectly satisfactory, since you can provide yourself with a simple Packard shutter to use behind the lens. Many portrait men actually prefer the Packard to the more costly between-the-lens shutters.
View cameras are more satisfactory than the press type cameras for portraits and are much less expensive.
The most specialized bit of equipment of all for portrait photography is the long focal length lens. It is imperative that you use a lens which will give a large image of the subject's face on the film without having the Camera closer to the subject than five or six feet. This means a focal length of around ten inches for 4x5 film.
The focal length of a lens is a fixed characteristic that determines the point at which a sharp image will be formed of an extremely distant object. Imagine the light ray from a distant point as a lever, which is pivoted where it passes through the lens, and which continues until it forms an image. When the point at one end of the lever moves, its image at the other end moves; the shorter the arm of the lever behind the lens ( a distance determined by the focal length), the less the image moves.
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Photography
