A leaked image of Sigma 24-105mm f/4 DG OS lens now on the web. According to rumors, this lens will be announced within 6 weeks.
This Sigma 24-105mm f/4 DG OS lens will be bigger and heavier than the Canon EF 24-105 f/4L IS and Nikon 24-120mm f/4G ED VR lens. According to the source, it will have an 82mm filter, weigh 885 grams (the Canon and Nikon verisons are 670g). The lens will have 19 elements in 14 groups.
There are also two other Sigma lens rumored to be announced in late 2013: Sigma 24mm f/1.4 DG and Sigma 135mm f/1.8 DG OS HSM.
via: CR