Canon camera lens marked red circle, green circle, white circle, what is the difference?
White ring: designed for the APS body design of the lens, full frame did not want to follow the cheap (can not use), but the lens "do" is indeed very "cheap", do not consider the price, then only EF-s17 ~ 55mmF2.8IS this One is really.
No circle: focal lengths have a repeat of the lowest file, such as 50mmF1.8, above the red circle 50mmF1.2L, 50mmF1.4 in the middle. Although it is the whole body of the body, but came up with no lap. The main feeling or let the cost of trouble, or rushed to the head of the sales volume is also enough to draw a purple circle powder bar
Yellow (gold circle): ordinary full-frame lens, work is generally not dust is not waterproof, the image is not much worse, the largest aperture is small, zoom head no constant maximum aperture, can not use a lot of aspheric, low dispersion lens is more likely to use fluorite.
Green circle: the use of diffractive optical components (DO components) professional-wide full-frame lens, currently only 70 ~ 300mmF4.5-5.6DOIS and 400mmF4DOIS two lenses, so do not know this technology is good or bad.
Red circle: professional full-frame lens, work good dust and water droplets, imaging quality is good (not necessarily), the largest aperture is relatively large, a variety of zoom lens aperture for the constant aperture, usually use multiple ultra-low dispersion lens, Spherical lenses even fluorite lenses.
