Why does my SF24 flash allow me to set the aperture on the flash unit in TTL mode?
I have searched the forums but can't find an answer to this.
I set my SF24 flash unit to TTL and attach it to my Leica M7 just fine. I have had some very overexposed shots in my forst few rolls of film. I was setting to TTL mode and ignoring any settings on the flash. The only thing I checked was that the exposure compensation was set to 0.
With some fiddling I discovered the SF24 flash unit allows me to change the flash setting on the flash when it is set to TTL mode. This is baffling as I understood that the camera measured the light coming through the lens and then cut the flash off when the correct amount of light had travelled through. Thus, when in TTL mode, aperture should be irrelevant. I've read the instructions to the M7 and the SF24 and they don't clarify this for me. It seems to me that 'A' mode and TTL are the same if I have to tell the flash unit what aperture I have my lens set to.
Could anyone tell me what I should be setting my flash to? Should I set it to TTL mode and set the aperture on the flash unit?
Thank you very much!
Baffled of Melbourne