Figuring out coating│Porro Binoculars VS Roof Binoculars Tips:
Under the same level of conditions, porro binoculars generally have a brighter field of vision than roof binoculars, and thus perform better. Because the internal glass structure of roof binoculars is more than that of porro binoculars, there are more reflections and greater light loss, so the light transmittance of the whole telescope will be reduced, but the top telescopes are generally roof binoculars.
For roof binoculars, the prism will divide the light in the light path into two beams, that is, the light will be divided into two halves in the prism, and then meet and recombine after passing through the half-silver coating prism surface. In the process of continuous reflection, the two beams of light will produce a phase shift phenomenon and a loss of incoming light, resulting in blurred imaging.
The phase correction coating is precisely to eliminate this phase displacement phenomenon to the greatest extent. After the phase correction coating process, the image quality can be greatly improved, and the color reproduction is more realistic and saturated, especially when observing against the backlight, or watching a gray-toned bird or other animals, see more color and detail.
【Phase coating comparison, the left picture has no phase coating, and the right picture has phase coating】
If the prism is not phase coated, there will be a star halo effect at the light source and often the sharpness is relatively low. However, the level of phase coating also varies, and some are just a gimmick, and it is not certain whether it will improve the quality of the telescope.
The main significance of coating is not only to increase the brightness, but also to reduce the glare caused by the reflection of our different lenses, reduce the dizzy and cloudy viewing effect caused by the reflection of the telescope, improve the saturation of the color, and make the observed object more prominent, so that we can get more immersed in the telescope viewing experience.