Just took delivery of a Sigma 85mm f/1.4 lens, and tried it with a Canon EOS 5D Mark II. I bought the lens for shooting indoor family events, taking portraits and maybe some still life shots. The attraction was a little reach with decent low light performance, and this seems to be a win. We'll see. Reviews rightly point out some problems with relatively slow auto-focus (so this is not a great lens for indoor sporting events), and the edges of the image are not terribly sharp when shooting wide open. That said, it is fairly easy to compose and shoot around these limitations with relatively static scenes.
Obviously, the depth of field is going to be very shallow when shooting wide open; and that is what these test shots are going to illustrate. Since I mostly shoot landscapes, I haven't played around with shallow depth of field much - particularly as I haven't had access to a lens that lends itself to this before.
The three images that follow were shot from about four feet away and are of some old hard drives. The center drive is about an inch forward of the right drive, and the left drive is about another inch further still into the background from the right drive (or about two inches from the front of the center drive). First, a shot focusing on the center drive:
The particulars: ISO 400, f/1.4, 1/125 sec. For the next shot, the focus is on the right drive:
The settings were ISO 400, f/1.4, 1/250. The last shot of this series was focused on the left drive:
The settings were ISO 400, f/1.4, 1/250.
The settings were ISO 400, f/1.4, 1/750; and the shot was from around 3.5 feet.
The final two shots are of some coins; again taken from about 4 feet away. A quarter is resting on the lens cap, and the machine screws are in the top right of each image. I do like the blur one can achieve for objects that are not the subject of the shot (i.e. the machine screws). The shots demonstrate how the depth of field changes with even a modest change in f-stop.
The settings were ISO 400, f/1.4, 1/250.
The settings were ISO 400, f/2.8, 1/60.
I think I am going to have a lot of fun with this lens.