# Faraday Cage - Wavelength and hole size

I read about the faraday cages and understood that the size of the holes should be very small than the wavelength of the signal for effective shielding.

But I am really confused due to the illustrations of the high and low wavelength signals.

Like, if there is a hole, of a certain size, doesn't matter about the frequency of the signal, the signals (assume a sine wave) with low amplitude , comparable to the size of the hole, will pass through and signals will amplitude higher than the size of the hole, will be blocked. But I know this is wrong. But due to the illustrations , I can think of only the amplitude to be the blocking factor.

Can someone provide an illustration as the why the wavelength of the signal is the limiting factor and not frequency or amplitude.

The frequency does matter. But that is because $$\lambda = c/f$$ - the wavelength and frequency aren't independent.