Different Types of Bearings: Their Applications and Working ... - bearing definition engineering
From wide to telephoto, this 15x high-power zoom lens covers a vast focal range, and it does it in a light, compact package. At the telephoto end, the 18-270mm is ideal for sports shots or when using distance to capture wildlife in habitat or natural expressions on subjects who normally would be overly conscious of the camera. Whether on vacation or in your own back yard, the wide end gives you the tools to shoot expansive landscapes. Every angle for photographic expression and all in a lens that delivers sharp, clear photos. In addition, this lens is packed with the best Tamron technologies, which have enabled a significant reduction in body size. The lens construction comprises 13 groups and 16 elements, which is two elements fewer than the previous model, while use of the hybrid aspherical lens with low dispersion glass has helped achieve a compact design and improved optical performance. In addition, the new PZD autofocus drive and the new VC mechanism were developed as downsizing technologies exclusive to Tamron. This has resulted in a compact lens that is 100 grams lighter and 24% smaller in volume compared with the previous model.
270mm tofeet
MTF (Modulation Transfer Function) curves describe to what extent the tested lens can faithfully reproduce contrast of the subject in images it captures. The closer the 10 lp/mm (line pairs per millimeter) curve (the thick line for low frequency) in an MTF chart to "1" of the vertical axis (the higher up), the higher the contrast reproduction performance of the tested lens will be. The closer the 30 lp/mm curve (the thin line for high frequency) to "1" (the higher up), the higher the resolving power and thus the subjective sharpness of the lens will be. Lens performance differs depending upon directions. Solid lines show performance in the sagittal (radial) direction while dotted lines indicate performance in the meridional (circumferential) direction. When sharp lenses capable of delivering uniform optical performance over the entire image field are tested, MTF charts show curves plotted in good balance. Performance characteristics of photographic lenses cannot be expressed with only MTF charts. There are other factors that are expressed in different methods, such as taste of softness and degrees of compensation of various aberrations. But you can use MTF charts as a scale to measure lens performance.
270mm toinchestofeet
The new BBAR (Broad-Band Anti-Reflection) coatings reduce the lens reflection and dispersion that cause ghosting and flare. The coatings enhance light transmission in both the short and long wavelength ranges, ensuring excellent performance in all photographic conditions. Additionally, internal surface coatings are applied to cemented surfaces of all lens elements to deliver sharp, high-contrast images and flawless color reproduction.
Release Date For Nikon: 2010/12/20* For Canon: 2010/12/20* For Sony: 2011/04/15* * Date of launch in Japan
270mm tocm
270mm toinches fraction
Tamron's celebrated VC (Vibration Compensation) just got even better. It still offers great handheld and telephoto shots. It still delivers the renowned VC (Vibration Compensation) stable viewfinder image, and excellent traceability. It's still based on a moving three-coil mechanism that activates the lens group electromagnetically through three steel balls. But technology must evolve. Previously, the heavy magnet was positioned near the lens element and worked very well in this placement. In the new VC (Vibration Compensation) mechanism, we've reversed the positioning of the magnet and connected the lens to the coils. This innovative new position thus achieves less load on the drive and combined with lighter coils, contributes to a lighter, more efficient lens. * VC is an abbreviation for Vibration Compensation, and is also available in the18-270mm (B003), 28-300mm (A20), 17-50mm (B005) and the 70-300mm (A005) models. * The Sony mount does not include the VC image stabilization functionality, as the body of Sony digital SLR cameras includes image stabilization functionality.
The new PZD (Piezo Drive) piezoelectric drive marks another Tamron first in its autofocus SLR lenses, an internal standing wave ultrasonic motor system. Innovations to reduce parts and simplify operation also contributed to the lens's reduced size and weight. Lighter and smaller than other autofocus drives, the piezoelectric drive uses a standing wave, instead of the traditional traveling wave, to turn and extend the piezoelectric element. Thus the entire element moves in a standing wave pattern, moving the metal tip (the contact surface) in an elliptic motion. The friction of this movement moves the rotor for a smooth, precise autofocus.
*1 Length, entire length, and weight values given are for the Nikon mount. Specifications, appearance, functionality, etc., may be changed without prior notice. *2 Length is the distance between the mount face and the tip of the lens. Entire length is the distance between the tip of the lens and the tip of the protrusion. *3 The Sony mount does not include the VC image stabilization functionality, as the body of Sony digital SLR cameras includes image stabilization functionality.
Designed exclusively for APS-C sized digital SLR cameras, this all-in-one zoom covers every angle. Its minimum focal distance of 0.49m (19.3 in) through the entire zoom range and macro capability to 1:3.8 allows you to enjoy serious, high-quality macro photography with unaccustomed convenience. With an optical system designed exclusively for optimum performance on digital SLR cameras with APS-C size image sensors, the angular coverage range of this lens is impressive. And even though it has built-in VC (Vibration Compensation), it still delivers a close minimum focus across the entire zoom range. From macro to telephoto this is a lens worthy of your creativity. Light, compact, smooth, and accurate at every angle. * APS-C size image sensors are smaller than the 35mm film format. This lens can produce full-screen images of almost the same scale (approx. 8cm x approx. 5.5cm) as those taken with a 35mm format camera with a lens of maximum zoom ratio of 1:2.5.