Both f/1.4 and f/1.8 lenses are pretty fast and they can both come in handy in low-light situations. Also, they both give you soft, creamy bokeh when wide open. Although the difference between these two apertures is not huge, f/1.4 lenses cost two or three times more than their f/1.8 counterparts. Is it worth paying extra cash for a slightly faster lens? In this video, Pierre T. Lambert uses them side by side and puts you on the test: can you tell the difference between f/1.4 and f/1.8?