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Canon PowerShot G7 Gordon Laing, February 2007

Outdoor
/ Resolution / Noise / Noise 2 / Corner sharpness / Fringe & macro / Geometry / Vignetting

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Canon PowerShot G7 wide-angle geometry comparison

Canon PowerShot G7 wide-angle geometry test  

To measure and compare the Canon PowerShot G7's geometric distortion we photographed a test chart consisting of a grid pattern, using it and a number of rival models.

Here are the results for each camera with their built-in or kit lenses at their widest focal length; where possible, the aperture was closed.

The images were analysed with Imatest using 5th Order line calculation and the full areas presented here at a reduced resolution.

7.4-44.4mm at 7.4mm
Distortion: 3.34% barrel

 
The image above was taken with the Canon PowerShot G7 zoomed-out to 7.4mm. Barrel distortion was measured at 3.34% which while virtually identical to the EOS 400D / XTi's kit lens, is measurably higher than both the PowerShot A640 and Panasonic DMC-FZ50.

Canon PowerShot A640
Canon 400D / XTi
(using EF-S 18-55mm)
Panasonic DMC-FZ50
Canon PowerShot A640 wide-angle geometry
Canon 400D with 18-55mm  wide-angle geometry
Panasonic DMC-FZ50 wide-angle geometry
7.3-29.2mm at 7.3mm
Distortion: 2.48% barrel
  18-55mm EF-S at 18mm
Distortion: 3.35% barrel
  7.4-88.8mm at 7.4mm
Distortion: 2.56% barrel


Canon PowerShot G7 telephoto geometry comparison

Canon PowerShot G7 telephoto geometry test  

To measure and compare the Canon PowerShot G7's geometric distortion we photographed a test chart consisting of a grid pattern, using it and a number of rival models.

Here are the results for each camera with their built-in or kit lenses at their longest focal length; where possible, the aperture was closed.

The images were analysed with Imatest using 5th Order line calculation and the full areas presented here at a reduced resolution.

7.4-44.4mm at 44.4mm f5.6
Distortion: 0.28% pincushion
 
The image above was taken with the Canon PowerShot G7 zoomed-in to 44.4mm. Pincushion distortion was measured at 0.28% which is the best result of the cameras shown here, albeit not by a huge degree.

Canon PowerShot A640
Canon 400D / XTi
(using EF-S 18-55mm)
Panasonic DMC-FZ50
Canon PowerShot A640 telephoto geometry test
Canon 400D with 18-55mm telephoto geometry test
Panasonic DMC-FZ50 telephoto geometry test
7.3-29.2mm at 29.2mm
Distortion: 0.35% pincushion
  18-55mm EF-S at 55mm
Distortion: 0.39% pincushion
  7.4-88.8mm at 88.8mm
Distortion: 0.34% barrel

Canon PowerShot G7 results continued...

Outdoor / Resolution / Noise / Noise 2 / Corner sharpness / Fringe & macro / Geometry / Vignetting


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