Back in the day they made those SLR lenses to last – and that’s a good thing for us DSLR users because there are a lot of old lenses available.
They are inexpensive and durable, with great optics, and you don’t need to use any DIY methods to make them work in your camera.
Recently I learned about a method for retrofitting older film lenses to function with our modern cameras. The possible bad news is that these are mostly manual focus prime lenses so your autofocus and metering won’t work (with one exception we’ll talk about later). The great news is that the majority of these lenses are built like photographic tanks and possess extremely capable optics. These lenses are also readily available and affordable on most any budget.
So how is it done? How can you make a twenty, thirty, or even forty year old piece of gear work with today’s advanced camera bodies? Believe it or not, the answer is deceptively simple. For virtually every lens and camera combination there is an adapter that will enable you to use any lens with any camera – regardless of manufacturer.
Don’t worry if this manual operation doesn’t appeal to you. The exception concerning the adapter rings I spoke of is that some are now being made with focus indicator chips built into the adapter. While this chip doesn’t enable you to use autofocus, it does allow the lens to communicate to the camera when the selected point of focus has been obtained.
Source: Digital Photography School