08-28-2011, 07:46 AM
[quote name='Brightcolours' timestamp='1314393531' post='11065']
Like popo points out: The sensor is 4x smaller in surface area. It collects 1/4th the light. Ergo: compare its ISO 100 with ISO 400 on FF. Or ISO 400 to ISO 1600. Equivalent sensitivity settings.
Yes, it is a 12mm f2 lens. However, its FIELD OF VIEW on 4/3rds is EQUIVALENT to 24mm (12mm x2) on FF. Its EQUIVALENT f-value (same apparent aperture) is f4 (f2 x 2).
So... no, with equivalent ISO settings, equivalent FOV and equivalent f-value (similar aperture), and similar exposure time, the sensors receive about the same amount of light.
Not only does a bigger aperture (for f1.4 on FF that is 3 stops bigger, an f2.8 lens still 1 stop bigger!) allow for more play in DOF, it allows for faster shutter speeds, it allows for lower light shooting.[/quote]
I'm not sure I follow this. Are you saying that if you mount the same lens on FF and MFT (via adapter) and use the same FL, the same aperture and the same ISO in both bodies you'd get a 2-stop difference in SS? I'm not a technical expert but I think SS will be the same.
Klaus, can you please comment?
Like popo points out: The sensor is 4x smaller in surface area. It collects 1/4th the light. Ergo: compare its ISO 100 with ISO 400 on FF. Or ISO 400 to ISO 1600. Equivalent sensitivity settings.
Yes, it is a 12mm f2 lens. However, its FIELD OF VIEW on 4/3rds is EQUIVALENT to 24mm (12mm x2) on FF. Its EQUIVALENT f-value (same apparent aperture) is f4 (f2 x 2).
So... no, with equivalent ISO settings, equivalent FOV and equivalent f-value (similar aperture), and similar exposure time, the sensors receive about the same amount of light.
Not only does a bigger aperture (for f1.4 on FF that is 3 stops bigger, an f2.8 lens still 1 stop bigger!) allow for more play in DOF, it allows for faster shutter speeds, it allows for lower light shooting.[/quote]
I'm not sure I follow this. Are you saying that if you mount the same lens on FF and MFT (via adapter) and use the same FL, the same aperture and the same ISO in both bodies you'd get a 2-stop difference in SS? I'm not a technical expert but I think SS will be the same.
Klaus, can you please comment?