I am anticipating and have high expectations for this "Di" lens to be released for the Nikon mount. Presently, Tamron has only released Canon mount version, while Tamron are still developing an AF motor into this A20 lens. This is going to be the first Tamron lens to feature a built-in AF motor and noteably the first "VC" lens. In Tamron's context, "Di" refers to Digitally Integrated design where the lens is suitable for full-frame (i.e. film or pro-range DSLR eg. Canon EOS 5D and Nikon D3 etc.) as well APS-C sensors DSLRs. "VC" refers to Vibration Compensation where it reduces vibration caused by camera shake (i.e. Canon's Image Stabilization, IS; Nikon's Vibration Reduction, VR; Sigma's Optical Stabilization, OS). The Tamron A20 is also an ideal walkabout lens covering the range of 28mm to 300mm (43 to 465mm for APS-C). This 10.7x zoom lens is made into a handy compact lens measuring 3.9-inches long only, making it a good travel lens which also saves the hassle of changing lens in the field.
Specifications at a Glance
- Lens Construction (Groups/Elements) 13/18
- Angle of View 75°23'-8°15' (APS-C size equivalent)
- Type of Zooming Rotation
- Diaphragm Blade Number 9
- Minimum Aperture F/22 ~ F/40 (28mm-300mm)
- Minimum Focus Distance (MFD) 19.3in.(0.49m) (entire zoom range)
- Macro Magnification Ratio 1:3 (at f=300mm, MFD=0.49m)
*1:2.33 (@ f-300mm, ref 3) - Filter Diameter ø67mm
- Weight 555g
- Diameter x Length ø3.06 x 3.9in. (ø78 x 99mm)
- Accessory Flower-shaped Lens hood
Nomenclature Codes for Tamron A20
- XR - Extra Reflective Index Glass
- Di - Digitall Intergrated Design
- VC - Vibration Compensation
- LD - Low Dispersion
- IF - Internal Focusing
- ASL - Aspherical
Distortions
Distortions seems pronouced for full frame at 28mm with slight pincushion at the 300mm (ref1, 2). Barrel distortions and pincushions are less pronouced when used on APS-C sensors (ref 1, 3).
Vignetting
There is hardly any signs of vignetting on an APS-C sensor but vignetting is obvious for a full-frame sensor at both widest and telephoto ends (ref 1, 3)
Sharpness
Tamron A20 produces excellent picture sharpness at 28 and 70mm, while quality drops to very good at 200mm and good at 300mm (ref 3). Full resolution sample pictures from users demonstrate the sharpness of this lens, convincing that a superzoom can be sharp as well (ref 2, 4, 5, 6, 7, 8, 9).
Bokeh
The bokeh from test pictures are creamy and smooth without much signs of orbs and donuts (ref 1, 4, 5).
Macro
Though published by Tamron to have 1:3 magnification ratio, tests have shown that in real life, a 1:2.33 magnification ratio is possible at 300mm (ref 3). That is extremely useful and is a plus point for such a superzoom lens.
Vibration Compensation
Users report a 2-3 stops advantage with the "VC" in Tamron A20 (ref 3, 4). The ideal weight and "VC" of the A20 makes this lens suitable for handholding in most situations, though working in low-light can be trickier than Nikon 18-200mm VR due to its smaller maximum aperture at the telephoto end.
Built
The Tamron A20 is made of polycarbonate in black colour with a matte finish. The 1.1 inch zooming collar is rather narrow for big hands but its well-placed position should make it easy to operate with the thumb and index finger. The frustratingly narrow 0.32 inch focusing collar is placed slightly in front of the zooming collar and is less used, unless manual focusing is required. Nonetheless, this lens does not have manual override of the AF. For the Canon mount, there are two switches, one for AF/MF mode and another for VC active/inactive. There is also a zoom lock at 28mm to prevent possible creeping which so far is not an issue. The lack of a motor results in high AF noise and tad slower AF. (ref 3, 4)
Verdict
In my opinion, I am definitely considering the Tamron A20 as my walkabout and travel lens, though it will not be ideal for dedicated photography where I would like to achieve 'hair-splitting' sharp quality at 100%. With the field reported 1:2.33 magnification ratio, I am thrilled by its Macro capability, which is better than any of my existing lenses. I am never bothered with AF noise but I do hope their new built-in motor will remedy this problem. I am impressed by the sharpness of such a superzoom which is very acceptable. I have always been pleased with the quality lenses from Tamron, from my experience with my trusted Tamron A16. Last but not least, the "VC" is very useable as reported and I am definitely thrilled about it!
Though I would expect the price to be higher than the Canon mount (~S$900), due to the AF motor. I am expecting this to hit S$1000-1100, when the Nikon mount hits our shores. That makes the retail price very close to Nikon 18-200 VR and more expensive than Sigma 18-200mm OS. This is going to raise a few eyebrows.
Next is to wait for the evaluation the quality of the Tamron A20 for Nikon mount and decide if this lens is going to justify its value.
I hope this mini compiled review is useful for you, it is for me. Thanks to all the resources from the kind reviewers in my references.
References
- Axel's PBase lens test gallery include full resolution pictures from Canon EOS 5D (full frame) and EOS 400D (APS-C) at 28, 50, 100, 200 and 300mm wide open and f/8.0.
- DC Watch review with full resolution pictures from Canon EOS 5D.
- PopPhoto.com review on Tamron A20
- Amin Sabet's blog reviews his personal take on the Tamron A20 with Canon EOS 5D.
- Amin Sabet's flickr gallery shows full resolution samples from Canon EOS 5D.
- Coshi's blog shows some full resolution samples from Canon EOS KISS DX (EOS 400D).
- Out-of-box review with 100% crop images that looks reasonably sharp with text at 300mm.
- With Canon 5D, A20 is taken to the streets for trial at all focal lengths and also night shots and panning. The images are all incredibly SHARP with 'HAIR-SPLITTING' SHARP' cat shots!
- More pictures byb kent106 to show off the sharpness and another 'HAIR-SPLITTING' SHARP shot.
- [OFFICIAL] Tamron A20
- [OFFICIAL] About Tamron A2 with VC Technology and Zoom Simulator.
technorati tags
Singapore Photography Lens Lenses Tamron Tamron A20 VC AF28-300mm f/3.5-6.3 XR Di VC LD Aspherical [IF] MACRO 28-300mm VC
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