18th July 2003, 04:21 AM
EXPERTS: Help! How does Spot/Eval/Center affect FEL? (i know how it affect AEL)
From what i know:
Pressing the FEL/AEL button during Av/Tv (fill flash) has 2 separate processes:
1. Calculates ambient light exposure.
2. E-TTL calculates Flash exposure.
***The question: ***
How do the different metering modes affect the 2 separate processes? I have heard that the metering modes ONLY affect AEL, and FEL always SPOT meters no matter what metering modeis chosen.
***Scenario illustrating my problem:***
1. Auditorium, with foreground target 2m away, and dark background (unlit stage)
2. Spot meter mode
Assuming i want BOTH foreground target AND
background to be properly exposed (all nicely lit up),
how is this possible?
If i FEL (spot meter) the Foreground target, the background will be underexposed, because EXPOSURE is calculated based on what is in the SPOT (which is the bright foreground).
If I FEL (spot meter) the background, E-TTL calculates flash output based on reflectance of the BACKGROUND, hence won't Foreground Target be OVEREXPOSED?
I know for higher end DSLRS, there is a separate FEL and AEL button. So one can LOCK exposure for the background, and LOCK FLASH exposure for the foreground target...Thus Background is nicely exposed, and enuff fill flash illuminates the FOREGROUND target w/o overexposing
However, D60s and below, only have a combined FEL/AEL button...
What do i do? I also still don't understand how FEL works in relation to SPOT/EVAL/CENTER metering...
Last edited by sprockett; 18th July 2003 at 04:24 AM.