Anyone else facing consistency problems with TTL?
I can't seem to find the internet source that discusses this in detail.
It is worth remembering that the flash metering system is heavily weighted toward the center of the image. I have found my results with CLS greatly improve when I put the subject in the center of the frame and use FV-Lock in TTL mode. Then, when I recompose the flash component doesn't change. If the subject is off center, your results with CLS TTL can be all over the place without using FV-Lock.
I was thinking CLS switched between TTL-BL and TTL when the metering was changed from Matrix to Spot. However, I can't seem to locate that in any manual, even though I thought it was. I must be mistaken on that.
With the built in flash on the D300 you have to be in Matrix or center weighted to get iTTL-BL (page 171 inm the manual). The SB-800 when mounted on the camera...iTTL vs iTTL-BL selected by the speed light but I think the area used for metereng can differe based on camera settings. When FV-Lock is used the metered area changes (page 180)
Here is the best source with lots of comments and discussion:
My opinions are my own and not those of DPR or its administration. They carry no 'special' value (except to me and Lacie of course)