Canon EF-S 18-200mm IS Geometric distortion
To measure the Canon EF-S 18-200mm IS's geometric distortion, we photographed a chart consisting of a grid pattern with the lens set to its shortest and longest focal lengths at an aperture of f8. The images were shot in RAW mode to avoid any in-camera corrections, then analysed with Imatest using 5th Order line calculation, and the full areas presented here at a reduced resolution. Smaller percentages are better. Results for rival lenses are shown at the bottom of this page; note the results for the EF-S 18-55mm here are for the older non-IS version.
Canon EF-S 18-200mm IS distortion zoomed-out |
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Canon EF-S 18-200mm IS distortion zoomed-in
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EF-S 18-200mm IS at 18mm f8
Distortion: 6% barrel |
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EF-S 18-200mm IS at 200mm f8
Distortion: 1.2% pincushion |
With the Canon EF-S 18-200mm IS zoomed-out to 18mm, barrel distortion was measured at a fairly significant 6%. This is approximately twice as bad as the EF-S 18-55mm, EF-S 17-55mm IS and the EF 24-105mm IS (on a cropped body) when all are zoomed-out to their widest focal lengths. It's also slightly worse than the 5.71% scored by the EF-S 17-85mm IS when zoomed-out. In reality, this means straight lines towards the edges of the frame, such as the edges of buildings or a horizon, can become quite distorted when zoomed-out. If you're used to the EF-S 17-85mm IS, then you won't notice much difference here, but it's comfortably more pronounced than many other lenses.
When zoomed-into 200mm, the EF-S 18-200mm IS, pincushion distortion was measured at 1.2%, which is slightly worse than the scores from the EF-S 17-85mm IS and EF-S 17-55mm IS. All three of these models exhibit noticeably worse distortion when zoomed-in compared to the EF-S 18-55mm and EF 24-105mm IS (on a cropped body). Again this means straight lines towards the edges of the frame when shooting with the lens zoomed-in can appear bent.
So the Canon EF-S 18-200mm IS suffers from quite noticeable geometric distortion at both ends of its range, but particularly at wide angle.
If you're shooting portraits or natural landscapes, you may not notice, but precision architectural photographers will find it unsuitable. Pronounced geometric distortion is one of the compromises with having a super-zoom range, and for the record, the Nikkor DX 18-200mm VR was no angel in this respect either, with measurements of 5.26% barrel distortion at 18mm and 1.22% pincushion at 200mm. Sigma and Tamron's super-zoom models also suffer from similar levels of distortion.
Now let's see how the lenses compare in terms of light fall-off in the corners in our Canon EF-S 18-200mm IS vignetting results.
Canon EF-S 18-200mm Geometric distortion compared to other lenses
Canon EF-S 18-55mm f/3.5-5.6 distortion wide / tele
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Canon EF-S 17-85mm f/4-5.6 IS distortion wide / tele
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EF-S 18-55mm at 18mm f8
Distortion: 3.35% barrel |
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EF-S 18-55mm at 55mm f8
Distortion: 0.389% pincushion |
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EF-S 17-85mm IS at 17mm f8
Distortion: 5.71% barrel |
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EF-S 17-85mm IS at 85mm f8
Distortion: 0.967% pincushion |
Canon EF-S 17-55mm f/2.8 IS distortion wide / tele
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Canon EF 24-105mm f/4L IS (APS-C sensor) distortion wide / tele
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EF-S 17-55mm IS at 17mm f8
Distortion: 2.87% barrel |
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EF-S 17-55mm IS at 55mm f8
Distortion: 1.09% pincushion |
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EF 24-105mm IS at 24mm f8
Distortion: 2.65% barrel |
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EF 24-105mm IS at 105mm f8
Distortion: 0.663% pincushion |
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