In the double slit experiment, I see that shooting electrons one by one, with a time interval between them, eventually creates a pattern that resembles that of light interference. But, before the passage of a long time and many electrons, I only see electrons at different places. So, if they say that the electron has a dual property, and light has a dual property, how can light exhibit that same shape - not pattern really - before that long time? I mean, the pattern produced by shooting electrons one by one, does that resemble the pattern formed by light? Imagine that we shoot photon by photon, will the same thing happen?
In the one-photon experiment you should see them. The problem is that it is very difficult to build a single-photon source and to make such an experiment.