kakashi has to active MS for Kamui but tobi doesnt?

[5kage]

Since kakashi has to active MS for Kamui why doesn't Tobi have to do the same to phase in and out, If it's the same technique?

 

[Mejkl3]

Post me picture wher you saw Tobi's Sharingan/MS while using Space-Time Ninjutsu U_U

 

[Gricay]

It's not the same technique. It just uses the same dimension.

 

[5kage]

That's what im saying, ive never seen him go MS but we always see kakashi has to do it to active space/time ninjutsu so why doesn't tobi?