Tamron Zoom Lens AF 18-270mm f/3.5-6.3 Di II VC PZD tested with EOS M

Aperture Range [f] 3.5-6.3 to 22-40 Closest Focus 0.49m / 1.6 ft.
Dimensions 96mm x 74mm / 3.8 x 2.9" Magnification Ratio 0.26x / 1:4
Weight 450g / 19.4 oz Filter Size 62mm

This is a very compact and and extreme power (15x) zoom lens that is made for APS-C sensors, 22.3x14.9mm, cameras. The tests here were made with EOS M mirrorless camera and Canon EOS 5D Mark III. It fits also a full frame cameras, but the image is smaller than the sensor (see the images on the bottom of this page). Due to it's zoom power is very versatile and attractive, especially when in travel. It focuses well, but slow, so it is generally not recommended for sports/action events, especially in low light.

Click on the "Various f-stops" thumbnail below, to see the charts made at different f stops and focal lengths. Only one circle chart is displayed: at the 12th mm from the center image (The center chart was always sharp, so that there were no significant differences). The sharpness was best mostly at f/11, but at wide angle settings the f/8 gave also good results.

I've tested this Tamron lens on 15 focal lenghts, 18, 25, 35, 54, 70, 76, 92, 100, 119, 142, 169, 184, 200, 246 and 270 mm. To see the charts in full magnification please click on the thumbnails below. Dependence of the image quality in various parts of the full 24x36mm frame is shown, with the average resolution in hundreds of line widths per picture height (LW/PH), given below each chart.

f stop dep. f stop dep. f stop dep. f stop dep. f stop dep. f stop dep. f stop dep.
Various f-stops, 18-76 mm
Various f-stops, 100-169 mm
Various f-stops, 184-270 mm
Tests at low fs
Tests at f/8.0
Various f stops with 5D mk III   low focal l
Various f stops with 5D mk III   hi focal l.

At wide open to f/11 apertures the lens sharpness is very good in the frame center but varies at the picture edges, where the sharpness is uneven in different line directions (see for the ranges of numbers under a single chart). At full apertures this effect is the strongest. The largest unevenness of sharpnes within one circle chart is in the middle of focal lengths.  For example, at 100mm corner chart one can count 3200 lines/p.h. when measuring from top left to bottom right and only 2000 lines/p.h. when measuring from bottom left to top right.  This seriously lowers the image quality. Somewhat lower resolution is observed at high focal lengths, but tests with the full frame 5D camera show that the lens is sharp all the way to 270mm, and perhaps less efficient image stabilization of EOS M is to blame.

Distortions in the corners vary with focal lengths.  For example the circle is almost 5% smaller at 18mm setting, and larger at all higher tested settings, being the largest by 8% at 54mm, and gradually smaller down to only 4% larger at 270mm. At the sides the circles are elongated, with a 7.1% difference in extreme ellipse axis 54mm. Than, with increasing focal length the ellipse effect generally decreases, and goes down to 4% at 270mm (although at some point between 18 and 25mm it should be 0). There is very little distortion at round 6mm from the frame center. Chromatic aberrations are the biggest problem of this lens, but only at the high ends of the focal lengths.

Compared to the Tamron Zoom Lens AF 28-300 mm, its performance is better when the sharpness and chromatic aberrations are compared (there is very little chromatic aberration between 50 and 100mm, but comparable at extreme focal lengths). Both lenses show variable sharpness in each single circle located away from the frame center, but the circles are generally cleaner generated by this 18-270mm zoom lens.

Compared to the Canon Zoom Lens EF 28-300 mm, its performance is similar when the sharpness around the frame center and chromatic aberrations are compared, but it is less sharp at the picture edges. Also, the Canon lens produces less distortions, however, some strange distortions observed in the Canon lens were not seen in this Tamron lens.

This lens is a great choice for APS-C sensor type cameras. The 4x image stabilization works well. Considering its the size, weight and price this would be the lens choice #1 for travel and strenuous hikes in the mountains.

f stop dep.
This lens mounted on a full frame camera covers significantly more useable area than the APS-C sensor does.


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