I found that the Canon R50 records the Canon CameraSettings' Focus Mode tag different than what's expected. The R50 has 3 focus modes; One Shot, Servo, and AI Focus. They're recorded in the file as 256, 267, and 258 respectively, and these are the numbers that ExifTool reports. However, ExifTool expects these values to be 0, 1, and 2, which is what you'd get if you applied a 0xff mask.
The exiftool.org Canon tags web page has 256 listed as 'AF + MF' and 257 as Live View, and it doesn't mention 258. The next two numbers are 512 & 519 for movie stuff, so my guess is anything above 0xff are bit flags.
When you got the values 256, 257 and 258, was this with Live View?
I agree about the high bits, but we really should figure these out.
- Phil
Edit: Wait. I just remembered the R50 is mirrorless, so in essence is it Live View all the time. What about decoding these as?:
256 => 'One-shot AF (Live View)',
257 => 'AI Servo AF (Live View)',
258 => 'AI Focus AF (Live View)',
Yeah, that seems good. FWIW I noticed that Canon DPP has 'Live View Shooting: ON' as a separate field in the Exif Information panel.
Good to know. Eventually maybe this should be split into 2 separate tags.
- Phil