Flash exposure intimidates pretty much everyone because it seems like it's so hard to predict and control. There are two aspects of exposure going on at the same time: the exposure from the flash on the foreground and the ambient light exposure on the foreground as well as the background. The truth is, these are very easy to manage.
There are two functions on our cameras that are used to deal with both aspects of exposure: [1] the exposure compensation feature (for ambient light), and [2] the flash exposure compensation feature (for the flash). If you don't know where these functions reside on your camera, it's time to find out. Check your manual. Every camera is different.
Here is the procedure I use when using off-camera flash such that I want to balance the lighting on the subject with the background as you can see in the outdoor shot above and the interior photo of a model on a staircase in a palace below. When I say 'balance the exposure', this doesn't necessarily imply that the foreground exposure is equal to the background exposure. In both of these pictures, you can see that the background is somewhat dark. This is what I wanted because that forces more attention on the subject, and it makes the subject more dramatic.
1. I put the flash on ETTL (iTTL
for Nikon users) and the
camera on Program mode.
2. I take a picture and then
examine it on the LCD monitor
on the back of the camera.
3. If the ambient light is too
light or too dark, I use the
exposure compensation feature
to make the adjustment. The
light can be affected in 1/3 f/stop
increments up or down.
If the flash exposure is not right,
I use the flash exposure
compensation feature to tweak
that. This also works in 1/3
f/stop increments.
These functions - the exposure
compensation feature and the
flash exposure compensation feature -- work independently of each
other. It's a simple matter of adjusting these controls to get what you want. Once you tweak the exposure, take another picture to see the results. If you need to make a further adjustment, do so and then shoot again.
In the past, professional photographers used Polaroid film to make test prints to judge exposure and lighting. Now we have the liquid crystal display (LCD) monitor to do the same thing. This takes the guesswork
out of flash photography because you can see the results immediately.
Don't make the mistake of thinking experienced photographers don't need this kind of trial and error approach to flash photography, and that if you can't get it right the first time, you are not doing something right. Trust me -- we have to do it exactly as you do.
FIRING THE FLASH
To sync the flash with the camera's shutter speed when it is used remotely, a connecting cord is obviously a hindrance to your freedom of movement. Therefore, a wireless trigger is the best way to go.
There are two choices. You can use a device that works on a radio frequency, like the Pocket Wizard, which is the best choice because if anything blocks the line of sight from the transmitter (which sits in the hotshoe of the camera) to the receiver (which fits onto the flash), it still functions without interruption. For example, the flash can be positioned behind a model with the person's head blocking the flash from view and it will still fire.
Alternatively, you can use a device that works on an infra-red signal such as the Canon ST-E2. This is less expensive and it works fine -- as long as the ST-E2 unit has a direct line of sight to the flash.
For Nikon users, there is a commander mode that uses radio frequency to fire the remote flash units.
PLACING THE FLASH
When photographing
people, using the flash at
arms length doesn't create
the type of angle you need.
Instead, the flash should be
placed at least at a 45
degree angle to the lens
axis. I typically use
off-camera flash between
45 and 90 degrees to the
lens axis. At 90 degrees,
the flash is lighting the
person directly from the side.
At 45 degrees, the angle of
the light is far enough away
from the lens axis to still
illuminate the subject with
artistry.
There are variations, too.
For example, to light the
couple at left I placed the
flash at a 45 degree angle
to the right but it was resting
against my photo backpack on the ground. Look at the shadow of the nose of the model on the right and you can see where the light is coming
from. This unorthodox lighting angle produced a different type of look -- and one that is a lot more compelling than using the flash on the camera.
Javanese bride
