What Does AL Mean In Photography? AL is an abbreviation of Aspherical Lens and is often used by the manufacturer, Pentax.  Please see the aspherical lens definition page for more details.   Additional Reading What Is An Aspherical Lens? What Does DO Mean On A Canon Lens? Pentax Lens Terminology And Abbreviations  


What Is Anti-Shake and how Is it Used In Photography? In photography an anti-shake system compensates for unwanted movement of the camera which would otherwise blur a photograph whilst shooting, for example hand holding a camera whilst shooting in low light conditions. There are two main types of anti-shake system; Lens based anti-shake uses a moving optical element to counteract shaking. Camera based anti-shake uses a mechanism which allows the image sensor to move to compensate for unwanted movement. Anti-shake systems are also extremely popular with videographers who’s cameras do double duty as both a stills and video capture system. …

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Apodization Filter

An apodization filter is a graduated neutral density filter that sits inside the back of a lens, and helps to smooth out the transitions in out-of-focus highlights or “bokeh balls”. Whilst the effect is most obviously seen in these highlight areas, as you can see from the Sony example below, the filter also causes a general smoothing of all OOF background areas. In short, if you want awesome, creamy looking bokeh, a lens with an APD filter is the way to go. So why haven’t we seen more of these lenses then, if they produce such a generally desirable result? …

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ASP Lens Definition ASP is an abbreviation for Aspherical Lens and is used by the manufacturer Sigma, to denote lenses which contain an aspherical lens element.  Please see the aspherical lens definition page for more details on this optical type.   Additional Reading What Is An Aspherical Lens?   Sigma 14mm f/2.8 ASP


ASPH Lens Definition ASPH is an abbreviation of Aspherical Lens and is used by the manufacturer, Leica to denote lenses that contain an aspherical lens element.  Please see the aspherical lens definition page for more details on this optical type.

Aspherical Lens

What is an Aspherical Lens? The term Aspherical Lens is slightly misleading, although it one that is often used in the camera industry. As you probably know, camera lenses are comprised of several different lens elements. Each lens element serves a specific purpose, such as correcting chromatic aberration or field curvature. An aspherical lens element is commonly used to correct spherical aberration, though it is usually only one or two elements within a more complex lens design. A spherical lens has a constant curvature to its surface. If you could extrapolate that curve, it would eventually come back around to …

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What Is Autofocus? Autofocus (AF) is the feature of a camera that tries to ensure that your chosen subject is sharp within the photo.  Sensors detect how far away the subject is from the camera, and this information is relayed to the lens, which then uses an electronic motor to adjusts the focal distance of the lens.  Most point and shoot cameras are autofocus only, but all DSLRs and mirrorless cameras have the option to disable AF if desired. The first autofocus cameras were developed in the late 1970’s and their speed and accuracy has been improved greatly since that time. …

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What Does Bokeh Mean When Talking About Taking Photographs? When talking about photographs the term ‘Bokeh’ refers to the quality of out of focus elements of an image. When taking a photograph you may not even think of the quality of the out of focus areas, but good bokeh, often appearing as smooth circular shaped objects in the out-of-focus areas of an image can dramatically improve the overall feel of a picture. The Quality of the bokeh in an image is often determined by the lens used to capture the image. Lenses that use an apodization element produce particularly soft …

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What Does Converter Mean When Talking About Photography? A converter, also referred to as a tele-converter or extender is a secondary lens which can be mounted between a camera and main lens. The purpose of a converter is to magnify the central portion of a lenses image area, therefore increasing the focal length. Typically converters come in either 1.4 or 2.0 magnification factors. When using an extender the shooter will sacrifice a small amount of lens speed (-1 stop for 1.4 and -2 stops for 2.0) and autofocus performance will also reduce slightly. Extenders also magnify any distortion caused by …

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What Is A Canon EF-S Lens? EF-S lenses are designed specifically for Canon APS-C sensor cameras.  It is not possible to mount an EF-S lens on an APS-H, or a full frame camera. Since crop sensor cameras do not make use of the full width of full frame lenses, you end up carrying around a lot more lens than is really necessary! EF-S lenses are lighter and smaller, because they don’t need to cover such a large image circle. Most popular EF-S lenses: Canon EF-S 24mm f/2.8 STM Pancake | Canon EF-S 10-22 f/3.5-4.5 | Canon EF-S 10-18mm f/4.5-5.6 IS STM   Additional Reading …

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