So, how do you use your grandfather's old manual focus lenses from the 1950s on your brand new 2012 digital interchangeable lens camera?
There are at least two ways to do this. One is to modify the old lenses to have the new mount of your camera. This is usually done when adapter is not available, or the even possible. The other, more common way, is through the use of lens mount adapters.
A small sample of my adapter collection
We won't be talking about the drastic lens modification option, since this is usually non-reversible and are expensive, not to mention finding the right person to do the job. Common lens mounts that get modified is Canon FD to the new Canon EF (EOS) mount, or Minolta MD to EOS, since these two mounts generally are not adaptable unless you use an adapter with glass elements. Lens mount modification is actually the best way to use old lenses on new cameras, because the converted lenses will behave like native lens on your DSLR, minus the auto focus/aperture function, unless you go the very best conversion with Contax N lenses for Canon EOS from the great Canadian company Conurus. The conversion itself will cost hundreds of dollars, so unless you have some really nice Contax N lenses, this is probably not worth it. Even the new mount that allows aperture settings on EF lenses for the Sony E-Mount costs hundreds of dollars, and it won't auto focus.
So, we will then be concentrating on the non-destructive adapters, but we won't be talking about the ones with glass elements, as these adapters basically act like a teleconverters which increases the focal length of the lens, as well as decreasing the maximum aperture, and at the same time degrade the optical quality of the lens.
Enough mumble jumble. Let's get on with it.
How do I know which lens will work with my camera?
We will discuss this in Part II.