sRGB has a gamma of 2.2. Why do the equations have an exponent of 2.4?
The simple answer is that the equations include both linear and power function parts and in combination they approximate a simple power function with an exponent (gamma) of 2.2. In other words, the 2.4 in the sRGB equations is not a “gamma” since it is part of a more complex function. Here is a more detailed explanation.
