Large-scale productions often distinguish between 3rd AD Floor | Base | Crowd.
The 3rd AD Floor is the right hand of the 1st AD on set.
The 3rd AD Base is the right hand of the 2nd AD.
And the 3rd AD Crowd is the right hand of the 2nd AD Crowd.
3rd ASSISTANT DIRECTOR
Large-scale productions often distinguish between 3rd AD Floor | Base | Crowd.
The 3rd AD Floor is the right hand of the 1st AD on set.
The 3rd AD Base is the right hand of the 2nd AD.
And the 3rd AD Crowd is the right hand of the 2nd AD Crowd.
The 3rd AD Floor often has only a few days of prep, if at all. Normally the PAs answer to the 3rd AD Floor and take on various tasks under his/her guidance.
In the US the 3rd AD Floor is called the 2nd2ndAD. In Europe 2nd 2nd AD is another term for the 2nd AD Crowd.
The key tasks are the guarantee of processes running smoothly on set and assisting the 1st AD.
The 3rd AD Base usually has more preparation time than the 3rd AD Floor, as s/he is involved beforehand in the costume fittings and make-up rehearsals and the rehearsals with the actors. S/he must have a solid understanding of all processes at the base in order to work independently.
The key tasks during the shoot are the supervision of the processes and looking after the actors at the base.
What the 3rd AD Base does NOT do!
The tasks listed below are the responsibility of the Unit or Set Manager, the Locations Department or the Transport Captain.
The 3rd AD Crowd is the right hand of the 2nd AD Crowd on set. In general the 3rd AD Crowd has little or no prep time, the exception being if s/he is assigned to support extras fittings.
Directing extras and ensuring smooth extras processes according to the specifications of the 2nd AD Crowd.