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4x4
#1 Đã gửi : 28 Tháng Năm 2006 1:34:54 SA

Danh hiệu: Trưởng lão



Gia nhập: 02/03/2006
Bài viết: 888
Điểm: -109
Đến từ: Somewhere, middle of no where

Có nên mua con này không này ko nh???

TAMRON INTRODUCES SP AF17-50MM F/2.8 XR Di II LD ASPHERICAL [IF]

 


 

Lightweight, Compact, Fast Standard Zoom Lens Designed for Exclusive Use
with Digital SLR Cameras (APS-C Size), Featuring True Wide Angle

February 15, 2006, Commack, NY —Mr. Morio Ono, President of Tamron Co., Ltd., announced today that Tamron will introduce in Spring 2006 the new SP AF17-50mm F/2.8 XR Di-II LD Aspherical [IF] (Model A16), a lightweight and compact fast standard zoom lens designed exclusively for digital SLR cameras with smaller size image sensors.*

*Di (Digitally integrated)-II lenses are designed for exclusive use on digital cameras with smaller-size imagers. This lens is not designed for use with 35mm film cameras or digital SLR cameras with image sensors larger than 24mm x 16mm.

The new SP AF17-50mm F/2.8 XR Di II LD Aspherical [IF] is a lightweight, compact, fast standard zoom lens designed exclusively for digital SLR cameras, expanding the product concept of the popular SP AF28-75mm F/2.8 XR Di zoom lens.

Two years after the SP AF28-75mm F/2.8 XR Di was launched as the standard for lightweight, compact, fast standard zoom lenses, it remains highly popular with advanced amateur and professional photographers alike. Now Tamron, moving with market trends, has unveiled a new design for fast standard zoom lenses used exclusively for digital SLR cameras that covers the easy to use angles of view: the focal length is equivalent to 26-78mm when converted to a 35mm format. In particular, the wide-angle focal length is established at 17mm (26mm equivalent) to obtain a wider angle of view than ordinary standard zoom lenses, while maintaining the remarkably lightweight and compact size of the earlier full frame zoom lens model.

In addition, portrait shots are made beautiful with the natural out-of-focus effect characteristic provided by the fast F/2.8 aperture. Additionally, a broader photographic expression through the use of faster shutter speeds as a result of the maximum aperture offers enhanced photographic pleasure. The minimum focus distance of 0.27m over the entire zoom range achieves a maximum magnification ratio of 1:4.5 at 50mm. The lens boasts one of the best close-up shooting performances in the class of fast standard zoom lenses designed exclusively for digital cameras and featuring an F/2.8 maximum aperture throughout the entire zoom range, to ensure stress-free photographic shots at all focal lengths and distances.

Main Features

Lightweight, Compact Fast Standard Zoom Lens is Designed Exclusively for Digital SLR Cameras, with 17mm Wide Angle Coverage
Exclusive design for digital SLR cameras achieves a fast standard zoom lens that covers virtually the same angles as focal lengths of 26-78mm when converted to a 35mm format. The wide-angle focal length is established at 17mm (26mm equivalent) to obtain a wider angle of view than ordinary standard zoom lenses, while maintaining the remarkably lightweight and compact size of the earlier full frame zoom lens model. Since the lens is designed exclusively for APS-C sized digital cameras, the image circle diameter has been reduced. Moreover, careful adjustments to the design have achieved a lightweight, compact body with a filter diameter of 67mm, overall length of 81.7mm (3.2”)*, and weight of 434g (15.3oz.)* (General design value).
* Values given are for Nikon AF cameras.

Optical System Uses Special Glass, and Is Optimized for Digital SLR Characteristics to Enhance Optical Quality in a Compact Design
The use of XR (Extra Refractive Index) glass in an innovative way optimizes the overall distribution of optical power, and also reduces various aberrations to the absolute minimum while achieving remarkable compactness. In addition, suitable positioning of two hybrid aspherical elements serves to maintain imaging performance and to shorten and compress the entire optical system. Furthermore, an LD (Low Dispersion) glass element is used to accomplish effective compensation of on-axis and lateral chromatic aberrations, a critical factor for enhancing optical quality in digital photography, in order to achieve outstanding optical performance over the entire zoom range.

Revolutionary Minimum Focus Distance of 27cm (10.6”) over the Entire Zoom Range Affords a 1:4.5 Macro Capability
The new lens achieves a minimum focus distance of 27 cm (10.6”) over the entire zoom range, the best in its class among fast standard zoom lenses with an F/2.8 maximum aperture throughout the entire zoom range used exclusively for digital SLR cameras with APS-C sized image sensors. The maximum magnification ratio of 1:4.5*1
at the 50mm setting is the top level in its class.
1 As of 15 th December 2005. Based upon Tamron research of lenses in the same class. 2 Since APS-C sized image sensors are smaller than 35mm film, t he 17-50mm can fill the frame with almost the same scope as a lens with a Max. Mag. Ratio of 1:3.0 on a 35mm SLR camera .

Optical Design Dedicated to Digital SLR Photography by Optimizing the Angle of Incidence of Light Rays Reaching the Image Sensor
This zoom lens uses an optical system designed to confine the changing angles of incidences of light rays reaching the imager within a certain scope over the entire image field by considering the effects of variance due to zooming.

Enhanced Peripheral Illumination
Peripheral light fall-off is minimized when compared with that of conventional lenses for film cameras, so images are uniformly bright from the center to the periphery.

Outstanding Resolution
Since the lens is designed exclusively for digital SLR photography, it provides high image quality resolution, contrast and flatness of image field .

Internal Surface Coating to Reduce Ghosting and Flare
By employing “Internal Surface Coatings” (i.e., multiple-layer coatings on cemented surfaces of plural elements) and new multiple-layer coating technology on ordinary elements, ghosting and flare due to the reflections that occur when light enters through the front element and reflections caused by the imagers themselves are reduced to the absolute minimum.

Large Aperture in Lightweight, Compact Design Thanks to New Mechanical Devices
Complicated mechanisms are built into the compact body, thanks to new mechanical devices, for excellent portability and ease of use. In addition, a complex triple cam structure where cams zoom and focus within a three-layer lens barrel has been further developed to improve AF focus precision for close-in shots and torque irregularity when zooming in and out. Additionally, the engineering of the lens has been completely overhauled to downsize its parts and to increase their precision and durability, in order to accommodate the complex structure incorporated into the new SP AF17-50mm F/2.8 XR Di-II LD Aspherical [IF].

Zoom Lock Mechanism Incorporated
The Zoom Lock prevents unwanted barrel extension when carrying the lens/camera combination.

Flower- Shaped Lens
A glare-reducing flower-shaped lens hood is included as a standard accessory. The special hood provides optimum shading of superfluous light rays that enter from the rectangular frame outside the image field.

New External Design of the New Di II Series Conveys “High Performance, High Precision Image”
Improvements have been made to the external design by adding a gold-colored band between the focus and zoom rings to enhance the appearance and make the product stand out as a Di-II lens. Also, the black coating over the entire lens barrel creates a high-quality, sophisticated look. The rubber patterns of the zoom rings have also been improved to complement the digital camera design style and to provide better handling.

Specifications
Tamron AF17-50mm F/2.8 XR Di II LD Aspherical (IF)
Focal Length: 17-50mm
Maximum Aperture: F/2.8
Angle of View: 78°45' - 31°11' (APS-C size equivalent)
Lens Construction: 16 elements / 13 groups
MFD: 10.6" (0.27m) (entire zoom range)
Max. Mag Ratio: 1:4.5 (at f=50mm, MFD 0.27m)
Diaphragm Blades: 7 (Circular Apertures)
Filter Size: Ø67mm
Size (Diameter x Length): Ø2.9 in. x 3.2 in.
Weight: 15.3 oz* (434g)
Standard Accessory: Flower-shaped Lens Hood
Compatible Mount: Canon AF, Konica Minolta AF-D, and Nikon AF-D

*specifications based on Nikon mount

4x4 hình được đính kèm:
17-50mm28 tamron.jpg (166kb) đã được dowbload 908 lần.
Nơi trú: http://www.taybacgroup.com.vn
ONE LIFE LIVE IT! ĐI, ĐI NỮA, ĐI MÃI

Nikon Vietnam http://www.vicvietnam.com
4x4
#2 Đã gửi : 28 Tháng Năm 2006 1:42:59 SA

Danh hiệu: Trưởng lão



Gia nhập: 02/03/2006
Bài viết: 888
Điểm: -109
Đến từ: Somewhere, middle of no where

Competitor of Tamron:

Sigma has announced a new 17-70mm F2.8-4.5 standard zoom lens designed specifically for APS-C sensor digital SLR cameras. The lens offers a minimum focusing distance of 20cm (7.9”) throughout the entire zoom range and a maximum magnification of 1:2.3 enabling extreme close-up photography.

Press Release:

Large aperture standard zoom lens designed specially for digital SLR cameras

  • Minimum focusing distance of 20cm,with an impressive maximum magnification of 1:2.3. at all focal lengths.
  • New design and multi layer lens coating reduce flare and ghosting.
  • Aspherical and SLD lenses offer excellent correction for various aberrations.
  • Large aperture of F2.8 at the wide angle setting.

The Sigma Corporation is pleased to announce the launch of the new 17-70mm F2.8-4.5 DC MACRO lens.The lens is ideally suited for a wide variety of subjects and is designed specifically for digital SLR cameras featuring APS-C size image sensor.

This revolutionary lens has a minimum focusing distance of 20cm (7.9”) throughout the entire zoom range. A maximum magnification of 1:2.3 enables extreme close-up photography. An impressive achievement for a standard zoom lens. The new lens design and multi layer lens coating reduce flare and ghosting, a common problem with digital cameras. A Special Low Dispersion (SLD) lens and two aspherical lens elements provide excellent correction for all types of aberrations and produce a high level of optical performance throughout the entire zoom range.
This lens offers a large F2.8 aperture at 17mm wide angle and yet it is compact, with an overall length of just 79mm (3.1”) and diameter 82.5mm (3.2”). Performance is superb, even in relatively low light conditions indoors or at dusk.

The lens design incorporates an inner focusing system, which ensures fast AF speed as well as preventing the front of the lens rotating, making it particularly suitable for use with circular polarizing filters and petal shaped lens hoods.
This lens is also equipped with a zoom lock that eliminates “Zoom Creep” during transportation.

Sigma 17-70mm F2.8-4.5 DC MACRO lens Specifications

Focal length

17-70mm

Minimum aperture F22 Maximum aperture F2.8 Lens construction 15 Elements in 12 Groups Angle of view 72.4°-20.2° Number of diaphragm blades 7pcs Minimum focusing distance 20cm (7.9") Maximum magnification 1:2.3 Filter size 72mm Lens hood Petal hood Dimensions Diameter 79mm (3.1in”)X Length 82.5mm (3.2”) Weight 455gr /16.0oz Optional accessories

• EX Filter Multi-Coated UV72 mm 0085126 912451
• EX Filter Wide Multi-Coated Circular PL72 mm 0085126 912550

Fittings • SIGMA AF
• NIKON AF
• CANON AF
• PENTAX AF
• KONICA MINOLTA AF
• Vignetting will occur if the lens is used with digital cameras with image sensors larger than APS-C size or 35mm SLR cameras

 

Nơi trú: http://www.taybacgroup.com.vn
ONE LIFE LIVE IT! ĐI, ĐI NỮA, ĐI MÃI

Nikon Vietnam http://www.vicvietnam.com
4x4
#3 Đã gửi : 28 Tháng Năm 2006 1:51:16 SA

Danh hiệu: Trưởng lão



Gia nhập: 02/03/2006
Bài viết: 888
Điểm: -109
Đến từ: Somewhere, middle of no where
Ghi chú là 2 con này giá same same.
Nơi trú: http://www.taybacgroup.com.vn
ONE LIFE LIVE IT! ĐI, ĐI NỮA, ĐI MÃI

Nikon Vietnam http://www.vicvietnam.com
4x4
#4 Đã gửi : 28 Tháng Năm 2006 2:10:30 SA

Danh hiệu: Trưởng lão



Gia nhập: 02/03/2006
Bài viết: 888
Điểm: -109
Đến từ: Somewhere, middle of no where

Đây là danh sách các loại Canon EF lens

Tập tin đính kèm(s):
EFLensChart.pdf (136kb) đã được dowbload 119 lần.
Nơi trú: http://www.taybacgroup.com.vn
ONE LIFE LIVE IT! ĐI, ĐI NỮA, ĐI MÃI

Nikon Vietnam http://www.vicvietnam.com
johnie
#5 Đã gửi : 30 Tháng Năm 2006 3:48:04 CH

Danh hiệu: Đồ chơi hạng nặng



Gia nhập: 03/03/2006
Bài viết: 488
Điểm: -1.286
Đến từ: Here, there and ev'rywhere

Về nguyên tắc thì lens 2 độ mở (Sigma f/2.8-4.5) so bì sao được với 1 độ mở (Tamron f/2.8 ), mà short focal length cùng là 17. Nếu so thì fải so với Sigma - AF 18-50mm f/2.8 EX DC. Còn không thì mua Tamron là sự lựa chọn khỏi fải bàn.

Đọc thêm về review ở đây:

http://www.photozone.de/8Reviews/lenses/tamron_1750_28/index.htm

Cũng ở đó có bài về Sigma.

Hy vọng là em Tamron mới này cũng xuất sắc như em 28-75 tiền bối.

Nhiều người đến, nhìn ngó
Vài người đến, nhìn thấy...
4x4
#6 Đã gửi : 30 Tháng Năm 2006 8:37:24 CH

Danh hiệu: Trưởng lão



Gia nhập: 02/03/2006
Bài viết: 888
Điểm: -109
Đến từ: Somewhere, middle of no where
Actual Focal length  35mm format "Effective focal length" on EOS 10D 14mm 22.4mm 16mm 25.6mm 17mm 27.2mm 18mm 28.8mm 19mm 30.4mm 20mm 32mm 24mm 38.4mm 28mm 44.8mm 35mm 56mm 50mm 80mm
Nơi trú: http://www.taybacgroup.com.vn
ONE LIFE LIVE IT! ĐI, ĐI NỮA, ĐI MÃI

Nikon Vietnam http://www.vicvietnam.com
4x4
#7 Đã gửi : 31 Tháng Năm 2006 8:31:28 CH

Danh hiệu: Trưởng lão



Gia nhập: 02/03/2006
Bài viết: 888
Điểm: -109
Đến từ: Somewhere, middle of no where
Dạ cám ơn anh Johnie. Em thì chuyên loại bắn B3-2 (trong half life), súng cự ly gần nhưng thích headshot.  , chớ có zoom bắn headshot nhàm.
Nơi trú: http://www.taybacgroup.com.vn
ONE LIFE LIVE IT! ĐI, ĐI NỮA, ĐI MÃI

Nikon Vietnam http://www.vicvietnam.com
4x4
#8 Đã gửi : 13 Tháng Sáu 2006 4:59:10 CH

Danh hiệu: Trưởng lão



Gia nhập: 02/03/2006
Bài viết: 888
Điểm: -109
Đến từ: Somewhere, middle of no where
Hehe, thông báo với các bác là AF của lens Tamron mới tĩ tã. Motor chạy êm lắm. Hình thì chưa dám bàn, để hôm nào có quả hoành tráng thì em sẽ giới thiệu.
Nơi trú: http://www.taybacgroup.com.vn
ONE LIFE LIVE IT! ĐI, ĐI NỮA, ĐI MÃI

Nikon Vietnam http://www.vicvietnam.com
DANG_BLUE
#9 Đã gửi : 13 Tháng Sáu 2006 11:30:39 CH

Danh hiệu: Tay bị tay gậy


Gia nhập: 22/05/2006
Bài viết: 22
Điểm: 6
Đến từ: HA NOI

4x4 đã viết:
Hehe, thông báo với các bác là AF của lens Tamron mới tĩ tã. Motor chạy êm lắm. Hình thì chưa dám bàn, để hôm nào có quả hoành tráng thì em sẽ giới thiệu.

Anh nhan xet ki ki ve con Tamron 17-50mm 2.8 di. Ma anh mua con day bao tien ay nhi?

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