 SCOTT R. SCHUITMAN |
Digital Photography: Getting Light Right We purchased the Canon Digital Rebel 6.3 in December. The flash was a 420ex speedlite. We did a wedding for the first time with the digtal. Shot in the program mode, ISO at 200 AEB at +1 - +2. ALL the pics were bright subjects with dark backgrounds. The camera store said to shoot at 400. This was a little better. We also bought a Canon 580ex speedlite. Thinking we needed more light to fill a dark church, we changed the ISO to 200 from 400. The pics were about the same. AEB bracketing from -2 to +2, the pics still seemed bright subject and dark background. We found the AEB at -1 looked better but still dark. Any suggestions? Scott
|
|
|
|
||
|
Jon Close |
A single on-camera flash cannot light both the subject and the background. Inverse square law - light intensity falls off proportionately with the square of distance from the source. Set to properly light a subject 10 ft. away, the light will be half as bright on objects 14 ft. away, and gives only 1/4 the light to objects 20 ft. away. In full program mode, the EOS cameras set exposure in a "snapshot" mode with relatively fast shutter speeds (1/60 and higher) that leave the background darker than the flash-lit subject. Adding + AEB probably had no effect in Program mode. With flash in P mode, the AEB is accomplished by changing the aperture only, and if you have an f/3.5-5.6 zoom, it was probably already wide open, so +2 would get the same exposure as +0. Slower shutter speeds are needed to give more exposure to the background (slower shutter speeds have no effect on the flash-lit subject). This can be accomplished by using Av or M mode. In these modes, the exposure scale in the viewfinder will be measuring the ambient light only, without regard for the flash, and the flash is used as fill-light on the near subject. Set shutter and aperture for "0" on the exposure scale, and the flash-lit subject and background will be balanced, to "-1/2" the background will get 1/2 stop less exposure than the subject. Take care to note the subject distance scale on the 580EX, and make sure your subject is well within that range. If you set the aperture too wide, a subject at the near end of the range or closer will be overexposed. See http://photonotes.org/articles/eos-flash/ for a comprehensive guide to using Canon's EOS flash system.
|
|
|
|
||
|
Maynard McKillen |
Dear Scott: As Jon mentions, your flash is providing more or less correct exposure for the subjects, but not for the backgrounds. Imagine using a radio-slave to trigger a second flash that is aimed at the background, but not at the subjects. Another approach, often used if the subjects are willing to remain stationary, is to set your camera in manual in such a way that it collects more of the available light. This method can also help you record backgrounds that do not appear as dark as they do when you use Program Mode. Let's say you plan to take some altar formals. Place your camera on a tripod, set the camera in manual mode, set the aperture at f/8, the ISO at, oh, 100 or 200, and take a light meter reading of the background before you put the subjects in front of it. Say, for instance, that your light meter recommends a shutter speed of 1/8th of a second. Set the shutter speed at 1/8th, make sure the flash is set to A/TTL or E/TTL, and fire a test shot of some willing subject. Take a look at the image on the LCD. I suspect the background will be lighter and the image more appealing than the ones shot in program. The flash is still providing more or less correct exposure of the subject, BUT YOU, the clever photographer, have set the camera to collect more of the available light. After experimenting, you may prefer to set the shutter speed so that the background is slightly underexposed, so that it does not compete for attention with your subjects. If the light meter recommended 1/8th of a second, for example, you might set the camera at 1/15th, effectively underexposing the background by one stop. HINT: A good time to practice said techniques is the night before the wedding, at the rehearsal. The Bride and Groom and the wedding party have to practice standing in the right places anyways, so you can take light meter readings in advance and find f/stop and shutter speed settings that provide pleasing exposures with backgrounds that are not too dark.
|
|
|
|
||
|
SCOTT R. SCHUITMAN |
Thank you for the information. We will be trying all of the comments. Scott Schuitman
|
|
|
|
||
|
This old forum is now archived. Use improved Forum here
Report this Thread |
||