I'm looking for an inexpensive cable release for my Canon EOS 40D. However, I plan on upgrading to a 70D somewhat soon. This is why I've been looking for a cable release that is compatible with both the 40D and the 70D. However, I haven't found a single product that lists both camera models in their list of supported cameras. Is the technology/jack for those fundamentally different? Or have I just not been looking in the right places?
The 40D cable remote uses what Canon calls the N3 connector, whereas the 70D uses the E3 connector. The E3 connector is just Canon's name for the subminiature 3/32" (2.5mm) 3-conductor TRS audio connector.
The N3 connector is just a 3-conductor connector as well (but I believe it is proprietary and only used by Canon).
They're physically different.
The 70D is the audio-jack style connector, while the 40D has the square, stubby connector (see, I know my technical words!)
Don't buy any of them from the Canon site (far too expensive), buy a 3rd party version from Amazon or similar, just check the reviews.