Relation between lens diameter and IQ
It appears that generally lenses with higher diameter (larger filter thread like 67, 72 or 77 mm) are much pricier than the lenses with comparatively less diameter (say 52 or 58 mm) and most of the cases they are better w.r.t. IQ too. Why it is so?
What may be the problem of manufacturing smaller diameter lenses with very good optics? Canon L lenses are also follows mostly the same trend. What is the technical reason behind this?