For much of my career in the film era, one of my favorite lenses was the Nikkor 35mm f/2. The focal length was great in the 35mm film era, and remains great in the digital era for several sensor sizes. Like its brother the 50mm, the 35mm prime (fixed focal length) can be manufactured inexpensively, can be made with a large maximum aperture, and remains small, lightweight, and inconspicuous.
A talented young friend of mine, Mackenzee Crosby, asked me recently about the Sigma 35mm f/1.4 Art lens. She shoots with a camera sporting a 24mm x 15mm sensor, so the Sigma isn’t really the right choice.
Ken Rockwell has a review of the Sigma, and spells it out pretty clearly about it: “Do not use this lens on Nikon DX cameras simply because the Nikon 35mm f/1.8 DX is as good optically, better mechanically and compatibility wise, and is smaller, lighter and less expensive.”
I recommended a lens to her that I have learned to love over the years, the AF-S Nikkor 35mm f/1.8 DX. Not only is this lens three or four times less expensive than the Sigma, it is lighter, smaller, and can render backgrounds – the real kernel of this class of lenses – just as beautifully as the Sigma.
As far as rendering backgrounds far out of focus, called selective focus, is concerned, the most powerful tool in the toolbox is the telephoto, not the wider-ish f/1.4s and f/1.8s. I recently talked about my 85mm, but the big guns, longer telephotos like the 70-200mm f/2.8, the 300mm f/2.8, and longer are the real kings.
Also for what it’s worth, I am incredulous that some photographers I know own very expensive large-aperture lenses that they use stopped down two or three stops. The only difference between a 135mm f/1.8 art lens shot at f/4.5 and a 70-300mm kit lens shot at f/4.5 is $1500.
Also, Richard, (you might be asking), why are my friends getting such amazing images with the Sigma 35mm? It’s simply that by shooting on a larger sensor, the 35mm focal length gives a wider field of view, requiring the photographer to get closer in order to fill the frame. Closer + large aperture = shallow depth of field.