Comapre two rasters with different extents

[LoisEvans]

I’m trying to compare vales of two rasters, however the rasters extent are not the same (but one raster is not smaller than the other, the extent differ in different places - see picture attached). I’m struggling to do this with the raster calculator as when I minus one from the other I do not get a difference form the full extent as some of the values has been set to NoData, so only get the difference where they overlap. Is there any way I can compare these rasters not only where they overlap but where they don't?

[DanPatterson_Retired]

extents are rectangular and will not follow your edge differences.

you will have some success using Con and IsNull to produce a mask yielding the cells that have values in both rasters.  Also make sure that you have a valid nodata value specified for the rasters

Conditional evaluation with Con—Help | ArcGIS Desktop