An apparatus and a method for detecting low frequency specular surface flaws on coated substrates is disclosed. A method for detecting low frequency specular surface flaws may comprise: impinging visible electromagnetic radiation or light from an electromagnetic radiation source onto the coated substrate at an oblique angle, reflecting the visible electromagnetic radiation off the coated substrate onto a screen material to form a specular surface flaw reflected image, and recording the reflected image off the screen material with a photosensitive device to form a recorded reflected image.
