I have a question relating to my Canon 400D and the new speedlite 430 EX II I recently acquired.

According to the Canon 400D Manual there is is customer function (page 105) called

Custom Function C. Fn8 for E- TTL II

The 2 options are

0: Evaluative : This provides fully automatic flash photography in all light conditions including automatic exposure compensation. The camera is integrated with the Speedlite and all you do with the Speedlite is turn the thing on, thats it, apparently.

1: Average: Geared for users who want to control the Speedlite. It averages the entire flash metering area (as opposed to what ?). Also in this custom mode the camera will not execute automatic Exposure Compensation, so it may need to be adjusted.

QUESTIONS

A. What does the evaluative mode measure for flash exposure if not the entire flash metering areas (option 1) ?

B. Do I have to have this custom function set to 1 not 0 to be able to manually manipulate the settings etc on the Speedlite ?

C. What are the advantages (if any) of having 'control over the speedlite' ? cf just leaving it as it is, automated via the camera ?


I guess the simple answer for a newbie to all this would be leave it in the default mode (0) and get more experience before you try going away from the automatic Speedlite via camera controls option, then think about changing to self control of the speedlite and manual setting/manipulations when you know more about Strobism.


If I did switch to the control the Speedlite option, I dont mind having to adjust the Exposure Compensation and have actioned a custom function that gets me direct quick access to EC by simply pushing the SET button after the shot if necessary to adjust the EC for the next shot. Im getting my head around FEL thingo too.

Comments and suggestions most welcome from anyone with more than my level of Strobism experience, which would be 0.