Implementation notes by Jan Brittenson (bson@rockgarden.net)
This is notes on the implementation and against http://www.burren.cx/david/canon.html.
The Canon makenote implementation has been tested against S100 and G1.
The S100 doesn't output focal length information; it leaves the fields zero.
Tag 0x8 (Image Number): the value 1000 should be 10000.
Tag 0x4 AF point isn't implemented since it's not really understood. I'll take a stab at it.
Both the S100 and G1 output tags:
TAG 0x2-3:2,672,285,214,
TAG 0x10-4:67371008,
The latter appears to be a long broken into two shorts. The high-end short is a large number, the low-end short a small number or zero.
Tag 0xc (Camera Serial Number) has been implemented but is untested since neither my S100 or G1 creates this.