Ratiometric Average Z projection, HELP PLEASE!!

[biomicrogen]

Greetings ImageJ Gods,

     I have a rather simple question (I think).  I am doing ratiometric intracellular calcium imaging through a Z stack.  I can not find much on the actual method of computing the various types of projections.  If I am making an ave z projection of my ratiometric stack how should I be interpreting the resultant image?  I have a feeling I may be misinterpreting my data.

I would appreciate any and all feedback or suggestions!

Thank you all!

Brandon