Working on my flash photography and need some help

I've been working on my off camera flash photography and having trouble getting my "subject" to be the center point with the light. Isn't there a way where I can increase the flash sync speed, bump up my aperture to f/22 or so and play around with the shutter speed? It's trial and error right?

I found if I go to what the camera says as correct exposure the spotlight effect on my subject isn't happening, everything get's exposed. I'm looking for the way that even during bright light (daylight) I can make my subject look as if under spot light and looking good and rest of the surrounding get's underexposed and looks dark. Does that sound right?

Help please

I'm no pro with a flash, but if I do recall there is a formula for determining correct aperture while shooting in manual mode.

aperture= Guide number (GN at ISO 100:m/ft) x ISO sensitivity factor divided by shooting distance (m/ft)

I had to look it up.

I just wrote about something similar on another thread. Hope this helps:

With flash. The aperture determines the amount of ambient light in a shot (as does ISO and shutter speed). Then the flash lights the subject (depending on various things). So if you use M for flash, it assumes the flash is the main lighting and will control the flash output as such. Then you can maniuplate the Aperture, SS and ISO to get the ambient light the way you want (dark background or lit). Generally I go 1 stop or so below perfectly exposed for ambient and let the flash sort out the subject lighting.

Shutter speed doesn't actually stop the movement of the subject when using flash, the flash will do this. However you might get movement blurring on the edges, sometimes in the reverse position it should be (like if you're photographing a car, the lights of the car might be out the front instead of the back) this is where you use reverse curtain sync or whatever your camera manufacturer calls it. This'll put the blurred sections of the photo behind the subjects motion where it should be (if your SS is too low).

Outdoors I use A or perhaps S mode. In these modes the camera assumes it's being used as fill (to fill in shadows) which is sorta what you want to use it for outdoors.

Hope that makes sense

P.S. your flash will also have a maximum sync speed (depends but usually it's around 1/200 or 1/250 see your manual for more information. You can overcome this by setting your camera to high speed sync, which will fire a series of very rapid bursts from the flash while the shutter moves over the sensor. This is useful when using your camera outdoors when you want a wide aperture for a blurred background.

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Very good information guys, thanks so much. I'm finding the information I was after. So I'm reading all of this and yet don't see where you calculate shutter speed? With my SB800 in manual mode I have found how calculate for correct exposure, how to obtain the correct flash output level and to calculate the shooting distance.

Area's that I'm still cloudy at is how to calculate or what do you I put my shutter speed at? Thanks so much!

Todd Knight wrote: I'm no pro with a flash, but if I do recall there is a formula for determining correct aperture while shooting in manual mode.

aperture= Guide number (GN at ISO 100:m/ft) x ISO sensitivity factor divided by shooting distance (m/ft)

I had to look it up.

Gotta love math.

The Gardener wrote: Very good information guys, thanks so much. I'm finding the information I was after. So I'm reading all of this and yet don't see where you calculate shutter speed? With my SB800 in manual mode I have found how calculate for correct exposure, how to obtain the correct flash output level and to calculate the shooting distance.

Area's that I'm still cloudy at is how to calculate or what do you I put my shutter speed at? Thanks so much!

You need some sort of light meter to get it right. Personally I use the one built into the camera.

Then if you're using manual of camera flash, you adjust the output of the flash till it exposes correctly. Like I said, set you SS for the ambient light (about one stop less than perfect). Then set your flash output for 1 stop of light. Adjust from there.