SPEEDLITE 540EZ

Top-of-the range in the EZ-series, and worth considering if you have a type B camera (and are unlikely ti upgrade to a type A camera in the near future). A-TTL flash mode. Guide number of 54 (ISO 100m) at 105mm zoom head setting.

Coverage down to 18mm using built-in diffuser panel. Tilt and swivel head.

EOS magazine, December 2003, page 38

Type: clip-on type automatic flash unit with direct-coupled contacts (including AF auxiliary light corresponding to 5 focusing points, A-TTL pre-flash, auto zoom and bounce functions)
Flash duration: 1.2ms or less during normal firing; 2.3 ms or less during quick firing.
Coverage angle:
• auto zoom mode: automatically set according to focal length of the lens in use (settings: 24, 28, 35, 50, 70, 80, 105)
• manual zoom mode: manually set by pressing the zoom button
• wide panel: flash coverage for super-wide-angle lenses down to 18mm is possible by covering the flash head with built-in wide panel
Flash modes:
• normal firing
• quick firing
• stroboscopic flash: stroboscopic frequency and no. of bursts each settable in 31 steps
• pre-flash: for measuring A-TTL distance information
• test firing: by pressing the test firing button
Flash head positions:

Exposure control modes: A-TTL program automatic flash, TTL program automatic flash, manual
Flash metering system: TTL automatic flash metering of light reflected off the film plane
Flash exposure compensation:
• automatic flash output reduction control provided in daylight fill-in flash situations
• manual compensation can be set on the flash within a range of ± stops in 1/3-stop increments. (possible in all shooting modes except fully-automatic shooting modes.)
• with some EOS models, flash exposure compensation is possible from the camera side by turning the main dial
Flash coupling range (50mm f1.4, ISO 100): A-TTL normal firing: 0.5~30m / 1.7~99ft, quick firing: 0.5~7.5m / 1.7~25ft (min) to 0.5~21m / 1.7~69.3ft (max.)
Flash change completion indicators: when the ready lamp lights red, normal firing is possible; when the ready lamp lights green, quick firing is possible
Auxiliary light & effective distance range: corresponds to 5 focusing points. Center: approx. 0.5~15m / 1.7~49.5ft (in dark situations); left/right: approx. 0.7~6m / 2.3~19.8ft (in dark situations)
Power supplies:
Built-in power supply:
• four AA-size alkaline-maganese batteries (LR6/AM-3)
• four AA-size Ni-Cd batteries (KR15/51)
• four AA-size lithium batteries
External power supplies:
• six AA-size alkaline-maganese batteries (LR6/AM-3)
• battery magazine TP (holds six C-size alkaline-maganese batteries (LR14/AM-2)
• Ni-Cd pack TP
Save energy function: when the main switch is set to the SE position, the power automatically turns off after 90 seconds of inactivity
Mode memory: The 540EZ automatically memorises its status information including the control mode and zoom position when the power is turned off
Dimensions: 80 (W) x 138 (H) x 112 (D)mm
Weight: 405g (main unit only)
Guide numbers (ISO 100m):

* The 18mm coverage angle figures are for when the built-in wide panel is used
• For guide numbers based on feet instead of meters, perform the following calculation: guide no. (ft) = guide no. (m) x 3.3
Battery life (No. of bursts) and recycle time:

* In the battery life column, figures on the right indicate the number of bursts in A-TTL mode, and figures on the left indicate the number of bursts in manual (1/1) mode.
The number of bursts possible at the 1/2, 1/4, 1/8, 1/16, 1/32, 1/64 and 1/128 manual power settings are greater than number of bursts possible at the full-power (1/1) setting by factors of 2, 4, 8, 10, 12, 15 and 18, respectively.
* In the recycle time column, the left-hand values are the flash recycle times in A-TTL mode, and the right-hand values are the flash cycle times in manual mode at full (1/1) power.