But I think he used lenses other just a 50mm Sonnar.
He quite liked 90mm for landscapes because it 'leaves out the bits you don't want to see' according to an interview from the 1960s that I read recently (not that you usually think of him as a landscape photographer)
Aside from the question of shooting sports, wildlife, etc. which are specialist cases...
I can see the argument that you'll miss shots if you don't have a lens of a particular length at hand.
However, the other side of that is that if you use a single length of prime lens you become accustomed to it: you know before you raise the camera to your eye how it will frame a scene, you know well the ins-and-outs of its performance at different apertures. You can anticipate a moment with greater accuracy and you'll be better at spotting those things that will suit
that particular focal length.
So, you may miss a shot because you don't have a 200mm with you, but, equally, you may miss a shot that's glorious for the 50mm, right in front of your nose, because you're thinking about all those other possibilities that are open to you. It's a particular discipline that can induce you to seek opportunities that otherwise you may not have considered. Know your tools well, and use them wisely
There are many parallels in other fields of the creative arts. Nobody criticises Charlie Parker for playing only the saxophone when he could have used other instruments and made music with the other sounds available with the piano and trumpet, nor Harold Pinter for not writing musical theatre. Ludwig Mies van *** Rohe's architecture was largely about the things he chose to leave out; he worked with a limited palette of materials a very specific concept of space and produced some stunning buildings.
In photography itself, the people who choose to work with large format film field cameras miss the opportunities afforded by a digital SLR, but it allows them to explore other areas of their creativity. I know she's the subject of some debate, but Sally Mann's recent exhibition in London of her work with the collodion wet-plate process shows that you don't need to be using every trick available to you with modern technology to create significant work.
It's certainly not for everyone, but it's an approach for which I have a lot of respect and I wouldn't dismiss it out of hand.
