Tamron lenses are often compatible with:. Tamron lens marking abbreviation and acronyms:. You might also be interested with the last entry in the blog:. N owadays our smartphones have more computer power than a 10 years old desktop computer. Technology is evolving fast and with it, the language acquiring new words like smartphone or selfie.
We are doing everything with our phone, from a GPS assistant to photograph or record a movie in full p HD, even post processing those images, and i don't even speak about playing 3D games, read some news on internet and so on At the end, when we compare how we use our phone the most, in percentage, I can say safely that we barely use it to call someone , and this is why i call mine a photophone.
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Nikon Z9 initial review. Sony a7 IV initial review. Nikon Nikkor Z mm F2. Normal optical glass has a relatively high color dispersion index, so that it comes to color hemlines in the image border.
With Tamron LD glass the dispersion is substantially lower, so that color hemlines are minimized in the edges. The lens hood is an important accessory in photography which prevents unwanted light from striking the lens and causing image flare.
The form of the lens hood depends on the angle of view of the lens and on the diameter of the front lens. A lens with a narrow angle of view needs a longer lens hood than a lens with a wider angle of view. See example below. If the front lens does not rotate while focusing or zooming IF Lenses , the lens hood can be built a little longer. Because, however, vignetting would first appear in the corners, these are left out.
This is how the flower-shaped hood got its form. The advantage of this construction, which is used with many Tamron lenses is the improved protection against stray-light at longer focal lengths. With longitudinal chromatic aberration the focal point position on the optical axis varies according to the wavelength.
This leads to blurred picture points and poor contrast. This characteristic is called dispersion and leads to undesirable side-effects, such as longitudinal chromatic aberration. The diagrams down below diagrams 01 underline the correlation: the first diagram shows the longitudinal chromatic aberration of normal glass. Only the middle wavelengths focus on the image plane. The second diagram clearly shows the reduction of this aberration through the application of LD glass.
LD Elements are produced of special glass materials which possess an extremely low color dispersion index a unit which measures the ability of a glass to separate a beam of light in its spectral colors. LD elements compensate for chromatic aberration, which is particularly a problem with telephoto lenses.
Chromatic aberration is a form of optical noise which reduces the sharpness and the brilliance of an image. Macro photography is the reproduction of small objects from a magnification ratio of approx.
Therefore, the larger the x value becomes, the smaller the reproduced image on the film plane becomes. The macro ratio is also referred to as magnification ratio, and the maximum ratio of a lens' reproduction capability is designated as "maximum magnification ratio". The luminosity is defined by the maximum effective diaphragm opening divided by the focal length of a lens. Lenses with wide apertures are especially required under unfavorable lighting conditions interiors without flash, animal photography in the dusk etc.
In addition, fast lenses offer a wider scope of creative potential. As a rule stopped-down fast lenses deliver better results than slower lenses at the same aperture setting. The minimum focusing distance is the distance between the object and the film plane or the image sensor of the camera at which a lens still illustrates sharply.
The minimum focusing distance together with the focal length determines the magnification ratio. The optical axis is an imaginary line through the centre of curvature of a lens. Simply: the center of a lens. There are two types of polarizing filters: linear and circular. Linear polarizing filters are made of mechanically stretched plastics with oriented rod-shaped molecules which are stained with a dye. For lenses there are glass-mounted varieties.
For lighting purposes large-sized foils are also available. The filters are used to convert unpolarized light into polarized light. The exposure factor amounts to about 2 - 3.
Circular polarization filters are used together with cameras systems whose exposure measurement works together with a mirror. This can result in an inaccurate measurement, because the measuring light can be polarized with the deflection.
Moreover, circular polarizing filters are necessary for autofocus cameras, because linear polarizing filters negatively affect the autofocus function, as they block out light from certain angles which is intended to reach the AF sensor. The effect of a polarizing filter is best demonstrated with a shining water surface. The polarizing filter causes a strong decrease in reflections at a certain position. Moreover, polarizing filters strengthen the saturation of colors of shining objects.
For example, the blue color of the sky becomes very intense, because annoying scattered light from certain angles is eliminated.
This is particularly true for slide photography. With optical systems the beams of light which come from infinity are broken to a certain focus. The imaginary plane where this happens is called the principle plane. The principle plane must not necessarily lie within the lens or the optical system. Ultrasonic motors are divided into two categories depending on the principle that generates the energy to move the drive: traveling wave motors and standing wave motors.
A standing wave ultrasonic motor utilizes high-frequency voltage to extend and turn the piezoelectric piezoceramic element, thus moving the entire element in a standing wave movement. A metal tip on the piezoceramic element is elliptically rotated by the rotary movement of the element and in turn drives the rotor by means of friction.
Standing wave ultrasonic motors have the distinct advantage of being smaller than their traveling wave counterparts, and therefore allow a more compact SLR lens size. The Tamron Piezo Drive distinguishes with its precise, fast and silent autofocus.
The Quad cam zoom mechanism is a zoom lens existing of four lens barrels. It is this special Tamron construction which makes the compactness of the 28 - mm possible. In photography resolution or resolution property refers to the ability of a lens to be able to return certain small detail structures. The resolution is measured in lines per millimetre and is dependent on the position for physical reasons the resolution is a little worse at the image edges than in the middle of an image.
Tamron lenses reach an optimal resolution property over the entire image field due to their construction by means of modern computer design. In photography a shutter is a light-tight, mechanically movable element which lies within a camera in the optical path in front of the image plane. During the exposure time this element is opened for the duration corresponding to the preset shutter speed, in which the light coming from the lens hits the image plane.
After exposure has occurred the shutter closes and protects the photosensitive layer of the film material or the digital image sensor against the unintentional incidence of light up to the next shooting.
Tele-converters are additional devices used between lens and camera and to increase the focal length of the mounted lens. The number stated in the name typically 2x or 1,4x represents the factor by which the focal length of the mounted lens is increased, e. Tele-converters are often an inexpensive alternative to an additional lens.
The disadvantage however is that that the luminosity of the mounted lens decreases in the same relation to the increase in focal length. The use of tele-converters is not recommended with long focal length lenses, wide-angle lens and so-called super zooms, as the image notably decreases.
Tele-zooms are lenses with a variable focal length starting from an angle of view of approx. This lens class is suited for capturing distant motives up close, e. But they are also classically used for portraits.
With this lens class the frame can be changed with a shift in the focal length zoom. Piezoelectric ceramic, an element that produces ultrasonic vibrations when voltage of a specific frequency is applied is arranged in a ring formation on the stator. This electrode configuration of piezoelectric ceramic causes two ultrasonic vibrations to occur in the stator. With the USD, the friction between these deflective traveling waves created on the metallic surface of the stator and the surface of the rotor produce force, causing the rotor to rotate.
The focusing ring of the lens, which is linked to the rotor, is thus moved, creating a fast and smooth auto-focus drive. The VC vibration compensation mechanism is a Tamron development which ensures an effective compensation for camera vibrations.
Especially hand-held, low-light and tele photography is susceptible for camera shake and consequent blurred results, due to the required longer shutter speeds. Under these photographic conditions the VC mechanism can unfold to its full efficiency. The VC mechanism includes a VC lens elements which moves parallel to the image plane merely via electronic control See illustration 1.
The driving coil unit includes a a position detector which assesses the respective position of the element VC and reports to the control unit.
The VC element has three magnets which are driven by corresponding driving coils. In the control unit, two gyro sensors are installed, which grasp the horizontal and vertical vibrations and report them to the micro processor.
The VC element is free-floating two degrees of freedom, and parallel to the image plane and can therefore compensate for vibrations in all directions. If vibrations occur as shown in illustration 2, a blurred picture originates on the image plane, proportionate to the rotation angle of the vibrations. The gyro sensors grasp the respective vibrations and report the data to the microprocessor. This in turn calculates the rotation angle and passes on the respective control commands to the driving unit which in turn shifts the VC element to counter the direction of the vibration.
The system works at a speed of 4 kHz, meaning that a correction is performed times a second. The VC driving unit uses a three-coil system developed by Tamron. The VC element is magnetically held in position, stored on three steel ball bearings. Since the VC compensating lens element is held in place solely by contact with these bearings, smooth, virtually frictionless movement is assured, providing stabilized viewfinder images and excellent tracking performance characteristic of VC lenses.
The result is an extremely short response time on grasped vibrations. Moreover, since the VC lens element moves parallel to the image plane via electronic control alone, the mechanical structure is simplified, and the lens is more compact. This serves the compact design concepts which distinguish Tamron lenses. There are two types of vignetting: natural and artificial.
Artificial vignetting is caused by components, such as the iris and fixtures among other things which lie in the optical path. These are to be dimensioned accordingly in the construction of the lens. With natural vignetting the intensity of illumination decreases towards the image edges.
In order to cover more subject area, a wide-angle lens illustrates smaller. A wide-angle reduces the image scale.
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