[Solved] The formula (equation) function

[Aliquippa Bill]

I'm going to be creating a lot of equations of the type {1 over %lambda}~=~R_H [{1 over n_f^2} - {1 over n_i^2}]

This may be a stupid question, but is there any way to increase the size of the brackets in the displayed equation AND ONLY THE BRACKETS?

[acknak]

{1 over %lambda}~=~R_H left [ {1 over n_f^2} - {1 over n_i^2} right ]