Find all TIFFs in a directory smaller than 90 MB:
$ find /dir/to/search -name *.tif -size -90M -exec ls -lh {} \;
Get just the size and path and write to a file:
$ find /dir/to/search -name *.tif -size -90M -exec ls -lh {} \; | awk '{print $5 , $8}' > output.txt
Useful for finding images that might have been scanned at the wrong resolution/bit depth/etc.