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Distance of measurement in reviews - marco - 10-20-2016
Like lens rentals showed it would be quite useful to know how far the 'wall' was away as you measured the lens properties. Sometimes they can change quite a bit. I think for wide angles they are quite far away from the normally used distance.
Distance of measurement in reviews - Brightcolours - 10-21-2016
That is correct, Marco. Sometimes a lens shows a defect at close distances which do not show up, or less pronounced, in normal usage distances. And then the lens in the MTF test performs worse than it will in real life usage.
An example of this is the Voigtlander 20mm f3.5 SL II. At close distance, astigmatism ruins the corners. At "normal" distances it actually performs pretty ok.