If it is a Canon EOS lens in the "EF" series then it can be used on ANY Canon EOS body.... film or digital. Model doesn't matter. You can think of the EF lenses as being universal in that they can be used on all EOS cameras.
The "EF-S" lenses (note the "-S" suffix) are designed for use on Canon's DSLR cameras that have APS-C size sensors. It turns the 70D does have an APS-C size sensor, so EF-S lenses are also valid choices.
There are "EF-M" lenses (I think there are only 2 lenses that were released in north america) which are designed only to work with Canon's "mirrorless" EOS-M camera.
There are also a few specialty lenses... the tilt-shift lenses are TS-E and there's a special macro photo MP-E lens. These also work with all EOS cameras (you can think of them like "EF" lenses) except they are specialty lenses -- not general purpose lenses.)
Canon currently markets some 72 lenses in the EOS line (not counting lenses they no longer make.) Of these... only two of them (the EF-M lenses) cannot be used with a 70D.
Tim Campbell
5D III, 5D IV, 60Da
