Using my studio lights outdoors I have been metering the ambient light on subject at f11. I then set my fill light at f8. My Canon 5D is on manual mode with a shutter speed of 125 and AP of f11. I then take the picture. My question is am I dragging the shutter?
I'm assuming that you are wanting some motion in the shot if you want to drag the shutter/2nd curtain sync. If you are metering your main and setting your camera the same and your fill is at f8, then you have a 2-1 lighting ratio, which really doesn't have anything to do with dragging the shutter.
"Dragging the shutter" refers to using a slower shutter speed than is necessary to achieve your exposure, generally when working with strobes or flash, usually to either blur motion or burn in ambient light when your subject is primarily exposed with strobe. When people use the term they're usually talking about shutter speeds like 1/60th or slower, not 1/125th (which is only 1 stop away from many cameras' max flash sync).
If I'm shooting concerts with flash, but want to get the stage lights to represent more or want the performers to blur a little, I might drag the shutter to 1/4th. If I'm shooting a portrait with a window in the background and I want to let a little more sunlight in I might drag the shutter to 1/15th. Those are more common situations.
I think Shatter nailed it again! When I drag the shutter, I'm usually shooting people at sunrise/sunset. I set my camera aperature to match what I am getting from a light reading off the flash on the subject. I then set my shutter speed to get the sky to look the way I want it.
