07-30-2010, 06:48 AM
[quote name='angrypizza' timestamp='1280426170' post='1394']
thank you for your reply, i saw the sigma 24-70 mtf graph with the d3 going somewhere around 3500 LW/PH f1/4 i thought larger fx lenses like this lens would get close to those values even with a dx camera but i can see with the link you gave me its a way lower than that . . disappointing . . so i guess this is a boost that only full frame cameras can provide with these lenses . .
[/quote]
LW/PH is line widths per picture height. Picture height is measured in pixels, so the (theoretical) maximum in our measurements is the maximum vertical image resolution of the sensor, regardless of its size (FX/DX). So, a 24 MP sensor with a resolution of 6000x4000 pixels shows scales up to 4000 LW/PH while a lower scale sensor (let's say 3750x2500 for a hypothetical 9.4 MP sensor) only scales up to 2500 LW/PH.
That's pure theory, though, there are quite a few factors which can limit the maximum resolution of a sensor and result in lower maximum numbers. A strong anti alias filter usually is the main reason for this, but the RAW conversion used can have a significant impact, too.
-- Markus
thank you for your reply, i saw the sigma 24-70 mtf graph with the d3 going somewhere around 3500 LW/PH f1/4 i thought larger fx lenses like this lens would get close to those values even with a dx camera but i can see with the link you gave me its a way lower than that . . disappointing . . so i guess this is a boost that only full frame cameras can provide with these lenses . .
[/quote]
LW/PH is line widths per picture height. Picture height is measured in pixels, so the (theoretical) maximum in our measurements is the maximum vertical image resolution of the sensor, regardless of its size (FX/DX). So, a 24 MP sensor with a resolution of 6000x4000 pixels shows scales up to 4000 LW/PH while a lower scale sensor (let's say 3750x2500 for a hypothetical 9.4 MP sensor) only scales up to 2500 LW/PH.
That's pure theory, though, there are quite a few factors which can limit the maximum resolution of a sensor and result in lower maximum numbers. A strong anti alias filter usually is the main reason for this, but the RAW conversion used can have a significant impact, too.
-- Markus
Editor
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