17-55 is always on the left side of the comparison photos. IS was turned off unless noticed otherwise.
Taken with 17-55 2.8, vignetting is visible
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F2,8, 1/2000, 50 MM, ISO 100
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F4, 1/1000, 50 MM, ISO 100
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F5,6, 1/500, 50 MM, ISO 100
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F8, 1/250, 50 MM, ISO 100
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F2,8, 1/125, 50 MM, ISO 100
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F4, 1/250, 50 MM, ISO 100
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F5,6, 1/500, 50 MM, ISO 100
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F8, 1/1000, 50 MM, ISO 100
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IS turned on. I didn't have enough time to do a more detailed test on IS affect on sharpness (I had this lens for a week). But it seems it doesn't soften the image, if it does, the difference is minimal.
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F2,8, 1/3200, 50 MM, ISO 100
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F5,6, 1/800, 50 MM, ISO 100
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