Great lens for what it is

[ericktodd]

This lens is a mixed bag for sure. For what it is its pretty impressive. On Full Frame its pretty much one of if not "the" fastest ultra wide angle lens. I would not really want to use this on crop sensor cameras, its not worth the trade offs.

This lens has the old manual focus clutch, switch system, which I have never liked. Further the ring is so big its really easy to pick it up and change from MF to AF.

At 1.8 the edges aren't great, but the center is. But hey it can do 1.8 what else can? By 2.8 I think its just as good as anything else, and at f8+ its great.

 

[Erlend_Saeteren]

I bought the 20 1.8 maybe twelve years ago to use on halfframe-format as standard slightly wide prime. It was good, sharp and fast. Later it has become superwide on fullframe. It will probably do that job for a couple more decades.