08-13-2014, 12:00 PM
Quote:I do think f1.8 for 9mm makes sense for a MFT lens. Usually the sweet spot of a lens is reached after stopping down about 2 stops from the maximum aperture. If the maximum aperture is f1.8 then the sweet spot would be around f2.8-f4, just corresponding to f5.6-f8 for a FF lens. If the maximum aperture is f2.8 then the sweet spot would be around f5.6-f8 but then diffraction already comes in for MFT.There is no reason to assume an f2.8 lens on MFT would be not sharp at f2.8. No basis for that claim. A bit too simplistic an argument, I fear.
In fact I think all primes for MFT should start the aperture from at least f2.