Assessing the exposure variation between two images

[Photosbykev]

Can anyone recommend some software that can take two Canon raw files and produce statistical data comparing two images please? The content of the image isn't important but it is a typical terrestial scene rather than astro.

I'm trying to get an accurate numerical assessment of the exposure variation between images taken with a precision timer with the camera in Bulb mode

[Jannis]

I have never even heard of a program that is made do this specifically to any files, canon raw or not, astro or not. But just out of curiosity, why do you want this exact exposure data?

[Photosbykev]

I'm trying to establish the mechanical variance from frame to frame taking into account the mechanical tolerance of the aperture mechanism and the shutter curtain timing. There's no point in making a precision timer with more accuracy than the in-built errors of the camera body