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Prime vs Zoom? [and 24-105 vs 24-70] Dxo reading suggest
  
 
alundeb
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p.2 #1 · p.2 #1 · Prime vs Zoom? [and 24-105 vs 24-70] Dxo reading suggest


After reading through this article again:

http://www.learn.usa.canon.com/resources/articles/2013/reading_MTF_charts.shtml

I found this paragraph:

" Canon MTF tests are performed only at two lens apertures

As noted previously, Canonís engineers publish MTF tests on Canon lenses exclusively at two apertures: wide-open and at f/8. Canon staff does not have MTF data for performance at other apertures. You cannot, for instance, determine from the available MTF data whether and to what degree optical performance at the smallest aperture, such as f/22, might suffer from the results of diffraction."

If he believes that diffraction effects may affect the MTF results at f/22 but not at f/8, he does not know what he is talking about.



Oct 23, 2016 at 07:31 AM
jcolwell
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p.2 #2 · p.2 #2 · Prime vs Zoom? [and 24-105 vs 24-70] Dxo reading suggest


alundeb wrote:
If he believes that diffraction effects may affect the MTF results at f/22 but not at f/8, he does not know what he is talking about.


Agreed.



Oct 23, 2016 at 11:15 AM
jcolwell
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p.2 #3 · p.2 #3 · Prime vs Zoom? [and 24-105 vs 24-70] Dxo reading suggest


Here's a quick summary of MTF diagram symbology for some popular MTF data sources.



© jcolwell 2016




Oct 23, 2016 at 04:10 PM
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