EOS R extender for EF lens - EF or RF?

[hakeae]

Hi, I have an EF 100-400 and am thinking about getting an extender - hmm but is it better to get an EF extender to match the lens, or an RF extender to match the camera?? I'm thinking it's going to come down to practicalities rather than optics and would need to be an EF so that I have body~RF-EF converter~extender~lens as body~extender~RF-EF converter~lens doesn't sound feasible  ... but maybe body~RF-EF converter~extender~lens isn't going to work either??

PS I'm a newb with this camera and in the forum, so be nice to me please. I got some condescending responses previously and it wasn't pleasant.

[Waddizzle · Accepted solution]

If you want a teleconverter for an EF mount lens, then you must use a teleconverter for an EF mount lens. 

If you wish to. Use an EF mount lens on an RF mount body, then you must use an EF-RF mount adapter.

I am not aware of a single device that can do both functions.

[hakeae]

That's what I thought, thanks for the confirmation. Just got distracted when I saw that an RF was available.