08-18-2021, 06:46 PM
A concrete example: you might choose Sony Zeizz planat 50mmf1.4 over Sony Zeiss Sonar 55mmf1.8 because you gain one f stop in low light condition, however in fact both are tf1.8, they have almost same low light performance, f1.4 version has a shallower DOF
https://www.dxomark.com/Lenses/
https://www.dxomark.com/Lenses/