Backlight or not?

[apetty]

Forgive me if this is the wrong place, I was at my daughters soccer practice last night and they were doing

pictures for the year. Now, this is an open field around sunset. The photog that was doing the shots had everyone

with their backs facing the sun and he used a fill flash (the flash was on camera, so I was a little concerned

about that too)

 

I was just curious as to why he would not have used the setting sun as the lighting for the pictures? Maybe set

the fill flash off to the side?

 

I am not a pro and I am not bashing this person, I am just curious about the technique.

[howard_m]

he created a rim light halo highlight effect around their head and used fill flash for the face. I'm sure it'll look quite nice w/o harsh shadows or squinting into the sun.

[Matt Laur]

Sun in face = squinting.

 

Flash on camera with no wall behind subject on which to cast shadow = very nice results.

 

The trick is to get the camera to meter for the background (so that it's nicely lit, and it doesn't look like their standing in a cave) - this is done with ISO and shutter speed - and then to understand your flash system's output well enough to know how get it to fill, just so - which is done with flash power control and/or camera aperture control.

 

Depending on how late it is in the day, the flash might need to be gelled a bit warmer so that it doesn't deliver a wildly different color temperature than the ambient light.

[apetty]

Matt, Howard, that makes total sense. This is why I am not a pro, yet ( I have not ruled out a future in photography after I retire from the rat race)

 

Thanx guys

[stephen_delear]

Am I right to think the trick to this would be to take a reading as your flash will see the scene (ETTL I guess), then take a spot reading off one of the faces and dial a correction factor into the flash equal to the f/stop difference between the two. The flash math here is getting me confused.

 

Lets say we have background 1/250 @ f/11 and

foreground 1/250 @ f/5.6

 

I need to throw two stops of light into the shadow to bring it into balance with the highlights. 1:4 Lighting ratio so on a studio flash set if for f/11 at the distance to target then dial in -1/4 stop compensation because 1/4 of the light energy is already reaching the target. (God I hope that's right it's been a decade since a last touched a studio light).

 

Now I would assume that a on the camera flash is going to give me an output for f/11. This would give me a slight over exposure, with TBH would be desirable is I was shooting film as it'd give me a little more detail any remaining shadows.

 

The Canon website however warns me that my flash might need to be adjusted upwards when dealing with a strong backlight. This makes some sense if the flash is going to assume that the subject is mostly exposed as read, f/11 + f/11 = 1 stop over, so I'm presuming that the flash will auto correct me a stop to two stops under? Would this be a constant or will the flash try to out think me and very it output unpredictably?

 

And am I missing something basic here? I have this little voice in the back of my head going "dial that a half stop off f/11 to prevent blown highlights" right next to the voice going "forget the math run a couple test shots and play with it."