Hi, In a double slit experiment, shooting a photon will produce interference pattern on a screen. Using a detector to detect which slit the photon passed through will destroy the interference pattern. The photon will pass through only 1 slit, and cause slit pattern on the screen. The screen detects photon using photoelectric effect, but since the interference is destroyed, is the original frequency of the photon still in tact? I ask this because the photoelectric effect depends on the frequency of the photon.