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Camera Lens Terminology

Learn the Terms to Know for Camera Lenses

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Camera Lens Terminology

This Nikon lens is an interchangeable lens for a DSLR camera.

Nikon
Although many parts of the digital camera are important, the lens might be the most important one. Without a quality lens, your photos have no chance of being sharp and bright. However it can be difficult to decipher the exact differences between lenses without knowing some camera lens terminology.

When shopping for a camera, make sure you pick the type of lens that will work well for your situation by learning the most important camera lens terminology.

  • Zoom. Zoom is the magnification of an image, allowing the photographer to shoot a "close-up" photo without having to move closer to the subject.

  • Optical zoom. Optical zoom is the magnification of an image using hardware inside the lens to change the focal length. Optical zoom is the preferred method of zoom, as it does not negatively affect image sharpness.

  • Digital zoom. Digital zoom is the type of zoom where software inside the camera magnifies the image. Because digital zoom involves increasing the size of the pixels, digital zoom sometimes can negatively affect image sharpness. When buying a camera, do not focus on digital zoom, as most photographers can duplicate most aspects of digital zoom with post-production software.

  • Interchangeable lenses. High-end, DSLR cameras can make use of interchangeable lenses, as different lenses provide different capabilities. With many interchangeable, DSLR lenses, image stabilization is built into the lens, limiting camera shake and improving image quality.

  • Focal length. The focal length is the measurement of the distance from the center of the lens to the focal point (which is the image sensor in a digital camera). Most digital camera lenses express the lens' range in a focal length measurement, such as 28mm-105mm. The focal length measurement more accurately measures the zoom and wide-angle capabilities of a lens than the optical zoom measurement.

  • LCD. The liquid crystal display (LCD) on the back of a digital camera can be used to frame a photo, like a viewfinder. However, keep in mind that the LCD rarely frames 100% of the image that the camera will shoot. LCD coverage sometimes can be 95% or higher, and the percentage sometimes is listed in the camera's specifications. It usually closely matches the view through the lens.

  • Optical viewfinder. The optical viewfinder provides a non-enhanced, non-digital preview of the image the photographer is about to shoot. With low-end, point and shoot cameras, the optical viewfinder is not tied to the lens optics -- instead, it's usually above the lens -- meaning it probably will not precisely match the image the lens will shoot. High-end, DSLR cameras tie the optical viewfinder to the lens optics, providing a perfect preview of upcoming image.

  • Electronic viewfinder (EVF). The EVF in a digital camera is a tiny LCD that gives the photographer a chance to frame the photo. The EVF is a digital representation of the image. In terms of mimicking the accuracy of the final photo, the EVF closely matches the LCD's accuracy.
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