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Canon’s Telephoto lens lineup

Canon’s Telephoto lens lineup

Including medium telephoto, telephoto, tele-photo zoom, and super-telephoto, Canon offers telephoto lenses for virtually any photographic application where you need to get closer to your subject without moving. Figure 6-22, taken at the 2004 Athens Olympic Games, was shot with a telephoto lens; the athlete, USA’s Mariel Zagunis, had no idea I was taking the [...]

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Telephoto lenses

Telephoto lenses

Telephoto lenses are perhaps Canon’s most distinctive products, easily recognized wherever they are used. Whether it’s a group of photographers at the Olympic Games or on the sidelines of the Super Bowl, photojournalists at a presidential press conference, or camouflaged war photographers in a battle zone, the long, white barrels are ever prevalent and always [...]

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Normal lenses

Normal lenses

A normal, or standard, lens features a focal range where images look very true to life — what your eyes actually perceive. Neither wide-angle nor telephoto, these lenses are the most common type used for portraits, head shots, events, and general shooting to achieve natural-looking images with limited or no distortion (see 6-17). I use [...]

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Wide-Angle lenses

Wide-Angle lenses

A wide-angle lens allows you to capture an entire scene, sometimes to the point of distorting elements of the image — which can be used for compositional effect, or it can just make your image look odd. Typically the focal range of wide-angle lenses begins around 24mm (known as superwide lenses, although Canon offers some [...]

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L Series lenses

L Series lenses

The L in Canon’s high-end lenses stands for “luxury.” L series lenses are easily identified by the telltale red ring around the end of the lens barrel (shown in 6-4). These flagship optical marvels are expensive, but provide unrivaled quality, speed, and precision. Canon has designated L series lenses for professional use, although many consumers, [...]

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Fast versus slow lenses

Fast versus slow lenses

A fast lens is a lens that provides a large aperture — meaning less than f/3.0. Why is it called fast, then? It is because a larger aperture provides more light for the digital sensor, meaning you can use a faster shutter speed in your images where there’s less light, as in 6-3. Consequently you [...]

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Zoom versus prime lenses

Zoom versus prime lenses

Overall, lenses are divided into two main groups: prime and zoom (see figure 6-2). A prime lens (also called a fixed lens) is one that has a fixed focal length, meaning the specification is a single length, such as 15mm or 200mm. A zoom lens has an adjustable focal length, meaning its focal length is [...]

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Vignetting

Vignetting

When light falls off of the edge of a photo, the periphery of the image is darker than the center, which is called vignetting. Essentially, light diminishes as distance increases from the optical axis, especially toward the corners of the image. This can be done on purpose as an artistic effect, such as in 5-11, [...]

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Pincushioning and barrel distortion

Pincushioning and barrel distortion

Pincushioning and barrel distortion are types of optical aberrations that distort an image from its real-world view as the human eye would see it. Barrel distortion is characterized by a decrease in image magnification as the distance increases from the optical axis — giving the typical fisheye look where it shows a bulging effect and [...]

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Evaluating color and contrast

Evaluating color and contrast

Understanding and judging color and contrast in your images are essential to producing good photography. Your lenses are where color and contrast begin and, to some extent, where they are controlled as they are processed as an exposure before being converted into a digital image. Histograms are available for you to use as an evaluative [...]

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Diffraction

Diffraction

When light travels through lens elements and through your aperture opening, some small amounts of it are diffracted, meaning dispersed and essentially no longer a part of your image. Usually the amount of light diffracted is negligible under normal conditions; however, it can occur when you are shooting with an exceptionally small aperture setting, such [...]

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False colors

False colors

False colors can occur when photographing subjects with detailed, high-contrast geometric patterns — whether it is clothing or the pattern on an object in a product shot. Your camera’s image processor can misinterpret the signals from the image sensor and add colors to the image that are not actually there. False colors are not a [...]

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Moire patterns

Have you ever seen a distracting pattern on a person’s jacket or shirt when watching television? This effect, known as a moire pattern, is caused by geometric elements of a subject and image sensor conflicting with one another. It’s one reason that portrait photographers generally advise clients not to wear geometric patterns in clothing when [...]

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Chromatic aberration

Chromatic aberration

While not very common with Canon’s current, superior lens technology, some lenses, such as very wide-angle and long telephoto lenses, can occasionally suffer from an effect known as chromatic aberration, or color fringing. This is when the lens elements do not converge the colors of refracted light precisely onto the focal plane (see figure 5-4), [...]

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Lens flare

Lens flare

Lens flare is the result of unwanted light entering the lens and hitting the image sensor. How the effect occurs depends upon various factors such as the number of internal lens components, lens focal length, aperture size and width, and the type of light source and its brightness (such as the sun, a spotlight, etc.). [...]

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Ghosting

Ghosting

Pointing a camera and lens toward a bright light of any kind can produce ghosting, which has two prominent features: an area of overexposure that is completely white and a part of the image that is streaked and patterned. It is caused by strong light reflecting from the image sensor back to the lens of [...]

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What is an Modulation Transfer Function chart?

What is an Modulation Transfer Function chart?

A Modulation Transfer Function (MTF) chart represents basically how a lens is evaluated. You can find these charts, for example, on the Canon Web site where lens descriptions are found; simply go to the product page for one of the specific lenses, and in the overview section they generally present an MTF chart for it. [...]

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What makes a lens good?

What makes a lens good?

What makes a good lens can be argued on a scientific basis or according to aesthetic considerations. Most people want a lens that produces a tack-sharp image with great color rendition for superior image quality. Certainly, how the lens handles mechanically is also important; it has to function as the photographer’s instrument and be able [...]

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Focal length and aperture effects

Focal length and aperture effects

While some photography technologies relate only to your camera’s internal operation, and knowing them won’t necessarily make you a better photographer, understanding some others can have a direct impact on your compositional skills and your ability to control your camera more completely. FOCAL LENGTH AND IMAGES Knowing the relative behavior of lenses, how focal length [...]

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Canon lens technologies

Canon lens technologies

Canon’s lens technology leads the industry in producing supersharp, high-resolution pictures. Optical engineering plays a fundamental role in the design of a dSLR camera, and consequently, lenses must also be engineered to even greater levels of precision. Through the development and use of such technologies as diffractive optics, fully electronic mounts, and image stabilization, just [...]

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