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Which Lens
Should You Use?
Ryan Salazar, Editor-in-Chief, Broadcast Beat Magazine
Here’s a little insight on lenses…
Choosing the proper lens is subject to several variables. Distance, lighting, and focus are all considerations, as well as the what, why, and when of the shot. Being a cameraman and being a photographer are similar, but definitely not the same as each group has their own gear and tricks. On the set, the unit still photographer has a very different job than the cameraman. In addition to being card-carrying members of the Cinematographers Guild of the Motion Picture Industry, these photographers have also formed an honorary organization: the SMPSP (Society of Motion Pictures Still Photographers), which was founded in 1995. Let’s explore some of their jargon.
A prime lens would allow us to have a compact lens. Such a lighter, smaller lens is usually faster and capable of a wide aperture – even f/1.4. The increased light this allows provides the use of fast shutter speeds to help freeze motion, which can be especially helpful in lower light conditions. That’s not all the increase in light does for us – it also brightens-up the viewfinder which, in turn, makes focusing, and thus the shot, as sharp as possible. Because of the shallower field depth of a prime lens, photographers – especially those shooting portraits – use the bokeh effect, which provides the image. The subject remains sharply focused but the background has a pleasing diffused softness to it.
A fisheye lens is much less commonly used, but if you need one for the type of shot you want to take, there’s really no substitute; sure, you could warp a normal image into a fisheye-style picture with the correct editing, but why go through the hassle? Digital fisheye effects cannot (as yet) stretch the angle of a view to equal the large image taken with a real (versus digital) fisheye lens. A standard fisheye image is set in a rectangular frame on a two dimensional surface. A fisheye-lens image is represented in
one of two ways with this medium of expression: either the circular fisheye, which is a round image on a black rectangular field, or the so-called full-frame fisheye, which is essentially a standard rectangular image taken by a fisheye-lens – except the edges of the circle are cropped off. A fisheye lens is used for IMAX filming and sees most of its additional uses at the planetarium, and with environmental mapping and flight simulators.
A zoom lens (aka “a parfocal lens”) includes multiple lenses housed in a mechanical assembly capable of varying the distance between its internal lenses, which lets it alter its own focal length and viewing angle. Zoom range is typically expressed as a ratio, thus a lens with a range from 150mm to 450mm would