Julian Loke wrote:
> Hello,
>
> I was looking through Canon's new EF Lens Work site.
>
> When comparing the MTF graphs for the EF 20-35 and 20/2.8, I was
> surprised that the theoretical MTF for the 20-35 looks very
> similar to the EF 20 f/2.8.
>
> http://www.canon%2Dsales.co.jp/ef/catalog/category/ef20%5F35%5Ff35%5F45.html
> http://www.canon%2Dsales.co.jp/ef/catalog/category/ef20%5Ff28.html
>
> I expected the EF 20/2.8 to show a greater difference.
> Did they make a mistake on the website?
> Are the graphs the same as in the paper version of Lens Work?
>
> Cheers
> Julian Loke
Hi Julian
Photodo's test results also seem quite similar:
EF 20/2.8:
Photodo testresultat:3,4
Effective focal length: 20
Weighted MTF for 20 mm: f2,8 0,65, f4 0,75, f8 0,77
Average Weighted MTF: 0,76 Grade: 3,4
Weighted MTF 10 lp/mm: 0,86
Weighted MTF 20 lp/mm: 0,70
Weighted MTF 40 lp/mm: 0,45
Distortion: -2,33%
EF 20-35/3.5-4.5:
Photodo testresultat:3,4
Effective focal length: 20 - 34
Weighted MTF for 20 mm: f3,5 0,72, f8 0,74
Weighted MTF for 28 mm: f4 0,76, f8 0,76
Weighted MTF for 35 mm: f4,5 0,77, f8 0,79
Average Weighted MTF: 0,76 Grade: 3,4
Weighted MTF 10 lp/mm: 0,86
Weighted MTF 20 lp/mm: 0,70
Weighted MTF 40 lp/mm: 0,46
Distortion: -4,55% - -0,89%
Regards,
Johan
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