05-01-2011, 03:13 PM
I had a look at the DXOMark website to find out pixel size of E-5 sensor versus D7000 one and just discovered their ‘lens test’ section. I got curious to find out about their reports on Olympus/Panasonic glass. There are only two lenses, the Oly ZD 35mm f/3.5 macro and the ZD 14-42 f/3,5-5,6.
Looking at the score of ZD 35mm, which is a respectable lens, they report a best resolution figure of only 36 lp/mm at MTF20 which would convert into a poor 936 LWPH (36x2x13) !!!! . The bottom glass of my wine bottle will probably do better than this. By comparison the best FF tested lens (Canon EF 85mm f/1.8) reaches a resolution of 67 lp/mm at MTF20 which equates 3216 LWPH (67x2x24); while the best APS-C lenses reach the 48-49 lp/mm mark or 1540 LWPH (49x2x15,7), according to them.
Looking at Photozone test of same lens, I can read “the resolution characteristic of the lens is generally on a very high level†and the graph shows a max resolution of 2278 LWPH at MTF 50 which is more stringent than the MTF20 used by DXO.
Where I am wrong?
Looking at the score of ZD 35mm, which is a respectable lens, they report a best resolution figure of only 36 lp/mm at MTF20 which would convert into a poor 936 LWPH (36x2x13) !!!! . The bottom glass of my wine bottle will probably do better than this. By comparison the best FF tested lens (Canon EF 85mm f/1.8) reaches a resolution of 67 lp/mm at MTF20 which equates 3216 LWPH (67x2x24); while the best APS-C lenses reach the 48-49 lp/mm mark or 1540 LWPH (49x2x15,7), according to them.
Looking at Photozone test of same lens, I can read “the resolution characteristic of the lens is generally on a very high level†and the graph shows a max resolution of 2278 LWPH at MTF 50 which is more stringent than the MTF20 used by DXO.
Where I am wrong?