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| p.3 #5 · Sony A7 and A7r Images and Discussion |
I rather like the passionate tone of the dear susan person, and MTF is a valuable tool, as a 'guide', so we can talk about Leica's mid field dips, for example. What inevitably happens in the absence of consistent methodologies, is that people will use whatever is around. This happens with all kinds of data. Sony are far from the only offenders in using 'promotional' MTF data.
The thing the market really needs is something comprehensive - with an optical bench for infinity testing and and flexibility for near distance testing and outcome reporting, based on a good sized sample of all lenses. The Imatest is another which has some controversy attached to it but is also still very useful.
Aberration analysis (beyond distortion and vignetting, the two least troublesome aberrations) would also be very helpful, as would actual images that show lens problems. Roger Cicala is on the case, here is a recent comment made on his site and a link to the article above it:
'The latter lets us take out paper and pencil and make a map of field curvature. More powerful benches will actually plot out the field curvature map for you.'