Kelly,
It was set to partial metering which I believe is the spot metering equivalent on my camera. And yes, by lowering the shutter it allowed MORE time for the light to get to the camera sensor.
I can't image your flash goes that far, but I would assume at full power it would at least go 25-35 feet and still be affective??
I'm happy to participate Kelly, I still have a lot to learn about exposure so sharing it on this thread reinforces what I learned by writing it down

Taking notes is not my strong suit and never was in school. This thread is a perfect excuse to force me to take notes

lol Plus you get the added benefit of helping people who still struggle with digital exposure's challenges.
Best,
Jay