Doubles and singles

In the UK we shoot at a rate of 25 frames a second in the US its 30 fps.  

Most feature films will shoot on singles, 1 frame for every move, but it is also possible to shoot Doubles - 2 frames for every movement.

I've shoot on both In my opinion they both have their place

Singles will give you smoother, more realistic animation.  Doubles are sometimes thought of as a quicker easier alternative but they to do have advantages.  They'll will give more "weight" to your characters and can make the look of your animation more "cartoony". It also gives you somewhere to go, you can mix singles in for quicker movements.  

On "Raa Raa the noisy Lion" the portions of the puppets where quite stubby  so we decided to shoot a mixture of doubles and singles and go with a more cartoony style which also suited the design.

Sometimes we'd shoot part of a shot on doubles then break into singles for part of a move, sometimes one character would move in singles whilst another in the same shot would be moving on doubles. 

I would recommend shooting any vehicles or more solid objects in singles as they tend to strobe, but the main rule is - any camera movements should be done in singles (pans, zooms, focus pulls, etc)