@mastodon
1) download the User Guide (see link in my signature, PDF file)
2) go to the index on page 1 and you'll see "Bad pixel notes", should be at page 55/56 (in the A4 version)
I couldn't explain it any better than fe50 did there ...
... and the manual should come in handy anyway
have fun,
wim
BTW: - 2 RAW pictures will be taken, takes 30 - 45 sec
- If "press Set to save ..." does not appear after 45 secs, press <Alt>, wait a sec, and again <Alt>,
(sometimes a CAnon screen refresh can overwrite the CHDK output, <alt> - <alt> will refresh screen)