02-09-2016, 09:53 AM
I use the NEX system since 2012. Thus I am always interested in tests of the e-mount lenses meant for the APS-C sensor size. Just browsing Photozone I discovered the very different testing results of the SEL 1855 obtained with a NEX 5 and a Nex 7. In particular the sharpness results drew my attention.
How is it possible that the same lens has much higher MTF50 scores for the NEX 5 than for the NEX 7.
I cannot follow the explanation by Photozone for this discrepancy. According to the explanations provided by the company that developed the test program, as they can be reached via Photozone, a higher number of mega pixels on an identical surface area (sensor size) must theoretically result in at least the same MTF50 values. Unless:
How is it possible that the same lens has much higher MTF50 scores for the NEX 5 than for the NEX 7.
I cannot follow the explanation by Photozone for this discrepancy. According to the explanations provided by the company that developed the test program, as they can be reached via Photozone, a higher number of mega pixels on an identical surface area (sensor size) must theoretically result in at least the same MTF50 values. Unless:
- Not the same lenses were tested, which would mean substantial variation in quality and unacceptable quality-control practices by Sony; I cannot find info in the test as to whether these tests were indeed done with the same lens or with different lenses of the same type.
- There is something wrong with the sensor of the Nex 7 used; hardly probable.
- The signal processing by the NEX 7 does something that specifically affects the sharpness of pictures obtained with the SEL 1855; also hardly probable.
- One or both tests were really flawed.