04-18-2013, 09:38 PM
Quote:Brightcolours, I've no idea how you calculate a f/2.8 - it has f/1.8 and you can't just multiply the aperture by the crop factor - that would only be fair, if the lens would have to bring enough light to a double as large sensor.
It's absolutely fair if you want to compare lenses with equivalent DOF. In this regard a f/1.8 lens on APS-C is the equivalent of a f/2.8 lens on full frame. Which also shows: there is actually no size advantage if you take as much as possible into account.
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