matrix inversion effect

Ok background, I have a 512 by 512 matrix of laser data (SPR). The laser data shows the stray light on the CCD we use. We then added the identity matrix, inverted and matrix multiply with a 512x1 signal (Lo), the stray light is removed from Lo.

A = inv((eye(512,512) + SPR))*Lo;

My question is I want to see how the inversion of the matrix (inv(A)) changes the relative effects of the different parts of the SPR on Lo.

The only way I can think of to do this is take SPR(1,1), make it 100, inv it and compare it to the original to see which parts of the matrix SPR(1,1) are affected. Then repeat this in a 512 by 512 loop.

I am not even sure if what I am asking makes sense. Any ideas would be greatly appreciated.

Thanks, Steph.