There is so much variation with the lenses that you buy – and a never ending discussion among photographers as well. I also sold a lens and just bought another copy that deemed to be a better lens.
This seems to be justfied as there are now empirical data by <a href=”http://www.lensrentals.com/blog/2015/07/variance-measurement-for-35mm-slr-lenses”>Lensrental</a> who measured the batch variance.
There is only one conclusion as far as the manufacturers never provide individuals MTF charts: <a href=”http://www.imatest.com/docs/sharpness/”>You need to check sharpness</a> as soon as you get a new lens. The USAF 1951 chart will probably not help so much; probably much bette are the <a href=”http://www.imatest.com/images/small_chart_contrast_20.svg”>Imatest charts</a>.
I wish there would be service providers who could analyse my test pictures.