Is f/1.4 really necessary?
Q In the past few months I've noticed a trend by companies to introduce lenses with an f/1.4 maximum aperture. Is an aperture this large really necessary in this day and age of high ISO sensors? Most, if not all, lenses with such a large aperture are next to useless wide open, with poor edge sharpness and bad vignetting. Yes, they let more light through the lens and into the viewfinder, which was useful in the days of manual focus, especially in low light, but in the days of autofocus, this would appear to be no longer the case.OK, some manufacturers, such as Zeiss, produce manual-focus lenses for AF cameras, but one of the facilities of viewfinders in pre-AF days was the ground-glass screen/split-image rangefinder, which…
