What are phase coatings?
Phase coating are a relatively new technology. These coatings are applied to roof prism binoculars only. Phase coatings are coatings applied to correct the phase shift of roof prisms which causes a deterioration of image quality.
In the past, even the best roof prism binoculars suffered from a loss in contract, resolution, and sharpness albeit ever so slight. In roof prisms, light waves reflected off of the prism deges are phase shifted(1/2 a wavelength of light) differently through each barrel of the binoculars.
The phase shifting of the light waves cause a reduction in optical quality. Once phase coatings are applied to the roof prism surfaces, the reflected light off of the roof prisms is phase corrected through each barrel of the binocular.
Thus, maximum resolution can be achieved for the particular aperture size and image sharpness and contrast are greatly enhanced.