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Olympus ZD 25mm uniformity comparison
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To measure and compare the Olympus 25mm's
vignetting and light fall-off we photographed a white target with a
highly diffused custom filter using it and a number of rival lenses.
Here are the results for each lens with its aperture fully open and the focus set to infinity.
The images were analysed with Imatest and the full areas presented here
at a reduced resolution. Bigger percentages are better. |
25mm at f2.8
Mean corner fall-off: 81.3% |
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| The image above was taken with the Olympus 25mm lens with its aperture wide open. Here the light falls off in the corners to an average of 81.3% of the centre
measurement. This is better than either score we measured for the 14-42mm kit zoom, although once zoomed-in, the 14-42mm comes close. The pancake's score is only fractionally better than the 50mm macro here, but its gradient shows a more gentle fall-off towards the corners which would be less obvious. So a good result here to end on for the pancake. Now let's see some real-life examples in our 25mm sample images gallery. |
Olympus ZD ED 50mm |
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Olympus ZD ED 14-42mm |
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Olympus ZD ED 14-42mm |
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50mm at f2
Mean corner fall-off: 78.6% |
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14-42mm at 14mm f3.5
Mean corner fall-off: 63.6% |
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14-42mm at 42mm f5.6
Mean corner fall-off: 85.7% |
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