philip_pj Offline Upload & Sell: On
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Here is Sony's wide open MTF (f1.8) and the 50/2 APO-Lanthar at f2. First one is certainly calculated, Cosina's appears to use a real lens (AL middle line pair is 30lpmm, not 20lpmm). This rapid fade of the FE55 in the outer frame (it loses almost half of its contrast by the corners) illustrates why the Voigtländer is such a revelation by comparison, when shooting at focal distances of 20m plus, even at f2 - flat field, very high and very consistent MTF. At f4 its chart is also much better than the Otus 55 as well, due to the Otus's significant outer frame dip and astigmatism at this aperture (all presumed at infinity).
For people not familiar with MTF, simply look at the bottom lines in each chart - the higher and flatter, the better. The left side axis shows contrast levels (performance). These lines scientifically measure how well fine detail is shown in your images, from the centre to the corner (left to right).
Sony 55/1.8 - f1.8
Voigtländer 50mm f2 APO-Lanthar - f2
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