Nailing Focus When Photographing Groups

[Shockey]

Sure there is a depth of field button...if you know how f-stops work you will probably never need to use it...unless of course you are doing some critical close up work.
When shooting people pictures the depth of field button is clumsy and pretty much useless unless you have a tripod and lots of time...certainly a situation where knowledge of f-stops would make using the depth of field button not necessary.

 

[icassell]

Until you are very comfortable with your camera/lens combination, the DOF preview button is an excellent way to learn -- people or stationary objects/ tripod or no. The OP obviously is still in this learning stage. This would answer the original question in an instant ... push the button -- is everyone in focus? If not, stop down some more ... I don't use it often anymore, but used it frequently during my learning curves (and still use it occasionally -- especially for macro images).