One of the sacrifices of going wide is sometimes you give up f-stops. Sigma wants you to have it both ways with its new full-frame 20mm f/2.
Generally, when it comes to designing lenses, you get your widest f-stops through the middle, and when you get super wide and super long you have to give up a bit of that iris.
Sigma is countering that argument with its new f/2 20mm I-series contemporary lens. It gives a pretty wide field of view (that’s 20mm for full frame, not just Super35) while sticking with the f/2 that runs all the way through the I series line up to the 65mm.
Author: Charles Haine
This article comes from No Film School and can be read on the original site.
