Questions about Canon Tc-80n3

The Canon EOS 70D requires a 3.5 mm plug for the remote release, so not compatible

Only the EOS Ra from the EOS R* series is listed in Canon's compatibility table. The TC-80N3 requires an N3 interface.

According to the Canon website it is compatible with the 5D markII

Yes, it works on the 7D mark I and mark II.

hello. i can't say if it's compatible with the 600D as i used it with a 5DMark III. but yes, you can take time-lapse pictures over a programmable period of time.

The thing doesn't look very high-quality, can do the most necessary things and is not particularly intuitive to operate. It does what it has to do, no more. I don't think any non-Canon product is significantly worse, if at all.

The manual does not say with which camera models the remote release is compatible, but if you go to the Canon homepage you will find the information very quickly: http://de.canon.ch/for_home/product_finder/cameras/digital_slr/eos_5d_mark_iii/#p-accessories5 According to this page, the trigger "TC-80N3" is listed as an accessory for the 5D Mk iii.