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Pentax *istDL wide-angle geometry comparison
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To measure geometric distortion
we photographed a custom test chart consisting of a grid pattern with perfectly
straight lines. Here are the results for the bundled lenses at their widest
focal length with an aperture of f8 in Aperture Priority mode. The images
were analysed with Imatest using 5th Order line calculation and the full
areas presented here at a reduced resolution. The image left was taken with the Pentax *istDL and the 18-55mm DA at 18mm f8. Barrel distortion was measured at 2.76% which superior to the group, although note vignetting is visible here even at f8. |
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Canon EOS-350D
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Konica Minolta Dynax 5D
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Nikon D50
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| 18-55mm EF-S at 18mm f8 Distortion: 3.35% barrel |
18-70mm DT at 18mm f8 Distortion: 3.49% barrel |
18-55mm DX at 18mm f8 Distortion: 3.51% barrel |
Pentax *istDL telephoto geometry comparison
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To measure geometric distortion
we photographed a custom test chart consisting of a grid pattern with perfectly
straight lines. Here are the results for the bundled lenses at their longest
focal length with an aperture of f8 in Aperture Priority mode. The images
were analysed with Imatest using 5th Order line calculation and the full
areas presented here at a reduced resolution. The image left was taken with the Pentax *istDL and the 18-55mm DA at 55mm f8. Pincushion distortion was measured at 0.58% which while barely noticeable, remains the worst of the group. |
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Canon EOS-350D
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Konica Minolta Dynax 5D
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Nikon D50
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| 18-55mm EF-S at 55mm f8 Distortion: 0.389% pincushion |
18-70mm DT at 70mm f8 Distortion: 0.309% pincushion |
18-55mm DX at 55mm f8 Distortion: 0.169% barrel |
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