Effects often called "flair" are caused by: Reflections. - Produces defined "ghosts". Bubbles in the glass. - Raises level of general light scatter reducing contrast. Other imperfections in the glass. - Raises level of general light scatter reducing contrast. Particles in the glass. - Raises level of general light scatter reducing contrast. Imperfections on the coatings. - Raises level of general light scatter reducing contrast. Imperfect surface polishing of the lens. - Raises level of general light scatter reducing contrast. Reduces sharpness. Gook on the lens. (clean it.) - Raises level of general light scatter reducing contrast. Can produce neat streaking rain effect. Scratches. - Raises level of light scatter reducing contrast. Overexposed areas produce "star streaks" normal to the direction of the scratch. (star effect) You can buy "filters" with straight "etches" to produce this effect. Reflections in film emulsion. - Causes "fuzzy" edges on overexposed areas (street lights at night, etc) Diffraction. - Causes "fuzzy" edges - limits resolution.
Ghosting is the only form of "flair" that can be mitigated by quality lens coatings.
Regards, Bob....
But absence of coating also raises the level of light scatter. A lens with multi-coating have less light scatter inside than a lens with single coating. Light scatter is precisely the principal source of flare. ???
Regards,
Andre --
