Switching Flash Coverage
Flash head (normal position)
The Guide No. is 22/72 (ISO 100 in meters/feet). The maximum flash coverage matches an EF 28mm wide angle lens
Flash head (pulled forward)
The Guide No. is 27/89 (ISO 100 in meters/feet). The flash coverage matches an EF 50mm
When shooting with a lens wider than EF 50mm
See p.26 for guidelines about the flash shooting range.
11