DSLR Canon Lens

Understanding Camera Lens

Now I have a problem that why sometime I takes a photo and my picture does not look like real image. I got the information and I think it is really help full for me and I think might be for you too to understand How does the Camera Lens do.

Understanding camera lenses

Understanding camera lenses can help add more creative control to digital photography. Choosing the right lens for the task can become a complex trade-off between cost, size, weight, lens speed and image quality. This tutorial aims to improve understanding by providing an introductory overview of concepts relating to image quality, focal length, perspective, prime vs. zoom lenses and aperture or f-number.

Lens Elements and Image Quality

All but the simplest cameras contain lenses which are actually comprised of several "lens elements." Each of these elements aims to direct the path of light rays such that they recreate the image as accurately as possible on the digital sensor. The goal is to minimize aberrations, while still utilizing the fewest and least expensive elements.

Optical aberrations occur when points of the image do not translate back onto single points after passing through the lens, causing image blurring, reduced contrast or misalignment of colors (chromatic aberration). Lenses may also suffer from uneven, radially decreasing image brightness (vignetting) or distortion. Try moving your mouse over each of the options below to see how these can impact image quality for extreme cases.

Influence of Lens Focal Length

The focal length of a lens determines its angle of view, and thus also how much the subject will be magnified for a given photographic position. Wide angle lenses have small focal lengths, while telephoto lenses have larger corresponding focal lengths.

Note: The location where light rays cross is not necessarily equal to the focal length, as shown above, but is instead roughly proportional to this distance. Therefore longer focal lengths still result in narrower angles of view, as depicted.

Reference: http://www.cambridgeincolour.com/