the colored rings on canon lenses mean chromatic aberration.
what do the colored rings on canon lenses mean?
chromatic aberration
na
na
third-party lenses compatible with canon's ef and ef-s mounts are manufactured by sigma, tamron, tokina and zeiss. the manufacturers of these lenses have reverse engineered the electronics of the ef lens mount. the use of these lenses is not supported by canon. however, many users find these lenses to be cheaper (with the exception of zeiss), and sometimes superior alternatives to canon lenses.





















































section::::lens mounts.:four thirds mount.
lenses for slr and dslr cameras