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Sony DT 11-18mm vs DT 18-70mm uniformity, shortest focal length
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To compare the vignetting and light fall-off of the Sony DT 11-18mm against the DT 18-70mm at their shortest focal lengths, we photographed a white target with a
highly diffused filter; each lens was focused to infinity with its aperture wide open. The images were then analysed with Imatest and the full areas presented here
at a reduced resolution. Bigger percentages are better.
Light falls off to 65.4% of the maximum when it reaches the corners of the Sony DT 11-18mm when it's zoomed-out to 11mm. This is roughly the same as the DT 18-70mm kit lens when its zoomed-out to 18mm, although the gradient is smoother on the ultra-wide lens and less noticeable in real-life. It's also a much better result than the Canon EF-S 10-22mm when it's zoomed-out, although the Sony lens isn't as optically fast. |
Sony DT 11-18mm
Using Sony Alpha A100 |
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Sony DT 18-70mm
Using Sony Alpha A100 |
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11-18mm at 11mm f4.5
Mean corner fall-off: 65.4% |
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18-70mm at 18mm f3.5
Mean corner fall-off: 63.3% |
Sony DT 11-18mm vs DT 18-70mm uniformity, longest focal length
To compare the vignetting and light fall-off of the Sony DT 11-18mm against the DT 18-70mm at their longest focal lengths, we photographed a white target with a
highly diffused filter; each lens was focused to infinity with its aperture wide open. The images were then analysed with Imatest and the full areas presented here
at a reduced resolution. Bigger percentages are better.
With the DT 11-18mm zoomed-into its longest focal length, the light falls-off to 62.2% of the maximum in the corners. This is actually pretty much identical to the kit lens at the same focal length, although again the gradient is subtle and it's a better result than Canon's ultra wide angle for EF-S bodies. Now for some real-life results, let's head on over to our Sony DT 11-18mm sample images. |
Sony DT 11-18mm
Using Sony Alpha A100 |
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Sony DT 18-70mm
Using Sony Alpha A100 |
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11-18mm at 18mm f5.6
Mean corner fall-off: 62.2% |
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18-70mm at 70mm f5.6
Mean corner fall-off: 87.7% |
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