To calculate the maximum energy loss in a photon-electron collision, use the formula ΔE = hf - E, where ΔE is the energy loss, h is Planck's constant, f is the photon frequency, and E is the initial energy of the electron. The frequency can be determined by dividing the speed of light by the photon wavelength. This calculation assumes a perfect elastic collision where all photon energy is transferred to the electron. However, real collisions may involve energy loss due to scattering or absorption. Understanding these principles is essential for accurately determining energy dynamics in such interactions.