The brightness of a binocular also enhances color differentiation in the image observed. Brightness is one criteria to be considered when purchasing binoculars, but is not the most important factor. In general, large objective lenses, low magnification and fully multicoated lenses are most desirable. Resolution A measurement of the binocular's ability to distinguish fine detail and produce a sharp image. Better resolution also delivers more intense color.
Resolution varies in relation to the size of the binocular's objective lenses.
Generally, a larger objective lens will deliver more detail to the eye than a smaller objective lens, regardless of the magnification of the binocular. Contrast Refers to the degree to which both dim and bright objects in the image can be differentiated from each other and from the background of the image. High contrast helps in observing fainter objects and in discerning subtle visual details. High quality optical coatings provide better contrast in an image. The distance between the binocular and the nearest object you can focus on, while maintaining a good image and sharp focus, defines the near focus of a binocular.