Canon 200-400 f/4 reviewed by "Chasseur d'Images"

Started Jun 20, 2013 | Discussions thread
mattr
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Re: Canon 200-400 f/4 reviewed by "Chasseur d'Images"
In reply to Oldvic, Jun 20, 2013

Oldvic wrote:

July issue, pages 106 to 109, field and lab test. CI tests for an A3 print size.

On the 5DIII, without internal converter (200-400):

- vigneting: from 0.7-1 stop at f/4 to near zero at f/11;

- CA: near zero at all focal lengths and apertures;

- distortion:same as CA;

- sharpness: about 92-93% from f/4 to f/11 and ending around 88% at f/22. The error bars, which indicate consistency, are barely detectable, and there's virtually no difference between the center and the corners of the image.

5DIII, with internal converter (280-560):

- vigneting: same as above but without the f/4 to f/5.6 interval, obviously;

- CA: slight increase, the fringes stay below 0.03mm from f/4 to f/16 and end around 0.05mm at f/32;

- distortion: around 0.4% pincushion at all focal lengths;

- sharpness: same as above, with the new f/32 aperture introduced by the converter hovering around 80% from 280 to 460 and dropping to 65% at 560 (f/32 aperture, remember). Again only at 560, the error bars become a little bigger but not by much.

They tested for sharpness at 560mm using an external 1.4x converter and found no significant difference for most apertures, f/32 being the exception: the external converter reaches a sharpness level of 80% as opposed to the 65% of the internal one.

Also tested the internal-1.4x external converter combo (800mm focal length), with a sharpness of around 87-88% at f/16 and a minimum of about 87% at f/32.

Next they tested the lens with an external 2x converter (800mm) and the results are as above with the 1.4x-1.4x combo.

Finally, they tested the internal 1.4x-external 2x combo (1120mm): sharpness drops to around 40-45% at f/11, around 60-70% at f/16, and tops out at 70% for f/22 and f/32.

Thanks for the info but it is very hard to take this test seriously.

The focus on differences in the f/16-f/32 range is utterly crazy. It also would be interesting to know what the % numbers are.

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