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Lens elements

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Lens Elements and Groups
When shopping for camera gear, you've undoubtedly encountered listings detailing how many "elements" and "groups" certain lenses have.


Lens elements
Techniques Glossary Lens elements
The individual pieces of glass that form the overall optical construction.

LENS ELEMENTS & IMAGE QUALITY
All but the simplest cameras contain lenses which are actually comprised of several "lens elements.

Lens elements.
5. Fine-tuning the Light
With a lens on the front of the camera, you can choose between having an image that's in focus or one that's out of focus but there really is no in between.

7 lens elements arranged in 5 groups including 2 aspherical elements
Micro four thirds mount
Closest focusing distance of 0.66' ...

" } , { "Title" : "AS" ,"GlossaryIcon" : { "Height" : "" , "Width" : "" } ,"HideInGlossary" : "1" ,"Summary" : "AS stands for Aspherical lens elements.

lens barrel - The tube that contains the lens elements.
lens cap - Hard, protective cover that clips over the front lens element when the lens is not in use.

A layer or multiple layers of thin anti-reflective materials applied to the surface of lens elements to reduce light reflection (flare) and increase the amount of transmitted light.
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Sometimes applied to an iris diaphragm whose blades operate between lens elements. SHUTTER, FOCAL-PLANE-A shutter located near the focal plane and consisting of a curtain with a slot that is pulled across the focal plane to make the exposure.

However, its not always easy to tell where the lens elements are. Check with your housing manufacturer for the best alignment.
You can use ports made out of optical glass or acrylic.

Glass is the most common material used to construct lens elements, due to its good optical properties and resistance to scratching.

So the zoom physically moves in and out shifting the glass lens elements inside the lens barrel to various positions to render the mathematical formulas necessary to create a series of lenses in a variety of focal lengths. Whew.

Schneider lenses of particular note include the Super-Symmar XL series with their aspherical lens elements. The 110mm f/5.6 Super-Symmar XL lens is extremely popular, and often listed as a "favorite" lens in many a photographer's arsenal.

Glass with ED properties indicating special rare earth glass or special formulated glass that limiting or correcting of light rays passing through the lens elements to achieve all spectrum of colours to falls on the same plane of focus - especially ...

Zoom lens can have as many as 18 lens elements but too many lens elements is bad for image quality due to light refraction and formation of flare between the many lens elements.

COMPOUND LENS - A lens made up of two or more lens elements.
COMPRESSION - Image files containing all the information recorded on a digital camera's sensor can be quite large.

However, a teleconverter does contain lens elements. A teleconvertor increases the focal length of a lens, but it does not change the minimum focus distance. This results in an increase in magnification.

Three UD (Ultra-low Dispersion) glass lens elements correct chromatic aberrations and floating elements ensure sharp definition at all subject distance. A ring USM provides silent AF and full-time manual focusing.

It has 2 clear lens elements; the front lens is the cornea which is fixed, and the flexible lens just behind the pupil which changes shape as we focus. There is a fluid filled cavity between the cornea and the lens.

Don't worry about things like the number of lens elements, type of glass used, or presence of aspheric elements. These can be indicators of a good lens, but too many lens elements can also be a sign of lazy design.

The new lens has been engineered for the ultimate in optical performance through the use of two fluorite lens elements for improved quality and reduced chromatic aberration.

The final solution to cleaning fungus from lens elements when all else fails seems to be toothpaste. My "UG" Nikkor-P 105/4 bellows lens was giving me decidedly foggy images.

6L is an interesting lens in that, while it's technically an L series lens with fluorite and UD lens elements, it doesn't have the tough build quality of a typical L series lens sold today.

This is a shutter that sits between two of the lens elements, typically somewhere in the middle of the lens in a mechanism that also incorporates the iris diaphragm. On a mechanical camera, its speed is usually set on the lens itself.

Cheaper lenses, especially those that come built into a compact camera, can often contain plastic lens elements.

Cause: Front and/or rear lens elements dirty. Solution: Clean with lens tissue and cleaning fluid. Use one drop of cleaning fluid on a tissue and clean lens in a circular motion starting from the center.

In a zoom lens, you can move different lens elements back and forth. By changing the distance between particular lenses, you can adjust the magnification power -- the focal length -- of the lens as a whole.
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Lens coating
Transparent coated on lens elements that helps reduce reflections and flare to improve image contrast.
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Zoom lenses contain more lens elements than a fixed-focal length or prime lens, and therefore aren't quite as sharp. Naturally, the angle of view decreases as you increase the focal length and magnify the image.

BETWEEN-THE-LENS SHUTTER - A shutter situated between two lens elements.
BITMAP - A bitmap is a picture that is an arrangement of tiny squares of different colors, called pixels. For the file extension, ".bmp," see .BMP below.

Flare
Reflected light from lens elements, metal, etc. Appears as a non-uniform haze or bright spots on the film. Usually occurs when bright light (such as the sun) enters the lens.

An overall decrease in contrast caused by light being reflected off, instead of transmitted through, a lens surface; controllable through the use of multilayer coating of individual lens elements in a lens; ...

So, being in focus simply means moving the lens elements forward or backward until all the rays coming toward the camera from the subject meet at one point; the focal point on the film.

Does anyone have any experience cleaning the inside of the lens elements?

With the sensor -- not the lens elements -- moving to overcome camera shake, any lens you mount on the Alpha becomes image-stabilized glass. Considering all of the old and new lenses that will fit this camera, how's that for a bargain?

Nikon introduced the first photographic lens with aspherical lens elements in 1968. Allows for more compact wide angle lenses, lighter and better performing than others with only spherical elements.

Contemporary lenses are invariably of the compund type. That is, they are made with multiple lens elements, combining to correct image aberrations. This is necessary because light is not single, unified source, but has different color and wavelengths.

Canon are keen to point out that the S60 has a lens which utilizes 'UA lens technology'. This has lens elements which have 'ultra high refraction index glass' which allows the entire lens system to be thinner (yet maintaining the same image quality).

-Supplementary lenses - additional lens elements used with the standard camera lens to provide a new focal length.

This could cause condensation on lens elements or ports when you enter the cooler water, or worse a flood from a popped "0" ring seal. Keep your equipment cool by covering it with a towel when you bring it on deck for the dive.

[Note that since most camera lenses are made up of more than one lens elements, the definition "middle of the lens' is adjusted slightly.] ...

Flare and ghostings are a major problem in contra-light situations. The problem is caused by reflected light - either from the lens elements or the inside of the lens barrel. There are certain techniques to reduce these reflections: ...

There are several other terms to take into consideration when buying a digital camera lens to make sure you are making the best purchase. If your lens utilizes aspheric lens elements, ...

Focus. A lens function that brings a scene or image into sharpness through the movement of optical lens elements inside the barrel of a lens.

Lens barrel - metal or plastic tube with a blackened inner surface, in which the lens elements and mechanical components of the lens are mounted.
Lens cap - plastic, rubber or metal cover which fits over the front or back of the lens to protect it.

Air Lens: A lens using an “air gap' (which has a refractive index of 1.0) between a pair of lens elements.

Fig. 1: For the sake of simplicity, this diagram shows only one lens element. In actuality, an interchangeable VR lens has many lens elements.

Image stabilization. A technology that compensates for camera shake, usually by adjusting the position of the camera sensor or lens elements in response to movements of the camera.

A major flaw with the G series: the need for lens barrel replacements every 6-12 months due to debris infiltration between the lens elements.

Extension tubes are hollow tubes of varying lengths that increase the focal distance of the lens by moving the lens elements further from the film or sensor. Extension tubes on current cameras generally disables the autofocus feature.

With two extra-low dispersion glass elements and three aspherical lens elements, the lens delivers high-resolution, high-contrast images while minimising chromatic aberration. Ideally suited for use on Nikon DX-format and FX-format cameras.

(Your condensed breath on the lens also works well.) Never put cleaning fluid directly on the lens; it might run between the lens elements.

Vignetting is darkening of the corners, usually occurring in cheap lenses and wide open apertures. Flare is caused usually by direct sunlight and due to reflecting of light between lens elements, due to poor coating.

See also: See also: Lens element, Element, Lens, Camera, Light

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