Flash and ISO Settings
When a subject is too close to a wall you will get shadows outlining them—and the shadows are different in each picture in the
stereo pair. To avoid this, move the subject farther away from the wall.
The price you pay for using higher ISO settings is noise—randomly spaced bright pixels concentrated in dark areas of the image. The more you increase sensitivity, the more noise you get.
If you get too close to a subject they may be seriously overexposed.
Red-eye can be caused by headon flash.
Most stereo cameras have a small built-in flash and no provisions, such as a hot shoe, to connect a more powerful unit. These cameras may give outstanding results in bright light, but struggle to produce good images in dark settings. There are only a few ways to improve your results and all of them come with problems of their own. For example, if you use the built-in flash you get harsh lighting. If you boost the ISO you get noise. However, there are some things you can do to improve your results.
- Make sure you are close enough. For example, on the Fuji W3 the auto flash's approximate effective ranges when the ISO is set to 800 is as follows:
- At wide angle it's 2 ft.–11.8 ft./60 cm–3.6 m.
- At telephoto it's 2 ft.–10.2 ft./60 cm–3.1 m.
- In 2D macro mode at wide angle it's 1 ft.–2.6 ft./ 30 cm–80 cm (wide angle).
- In 3D macro mode at telephoto it's 2 ft.–4.9 ft./60 cm–1.5 m.
- Increasing the ISO lets you photograph in dimmer settings with a faster shutter speed and smaller aperture than you could otherwise use. Unfortunately higher ISOs create noise that can diminish the quality of your images. When the ISO is set to Auto, you have no control over the setting that's used. If you can set it manually, selecting a lower ISO may reduce noise. However, lower ISOs often require slower shutter speeds which also create noise or result in blur due to camera or subject movement.
- Increasing the ISO increases the range of the flash.
- Since a built-in flash can't be rotated to bounce light off a wall of ceiling to soften it, flash photos are usually harshly lit —often an overexposed person in front of a black background. The one flash mode that can change this is called slow synchro although some camera companies call it night portrait mode. In this mode the camera fires the flash to illuminate the foreground subject then leaves the shutter open a little longer to lighten the darker background.
- The light from a flash falls off dramatically with distance. To keep everything in the foreground evenly lit, position your subjects or camera so the most important subjects are all the same distance from the camera.
- Try to get more light on the subject. In some cases just moving someone so they are in the light coming through a window, or in the warm orange glow of a tungsten lamp will be enough.
- Use a slave flash. There are flash units designed to fire when they sense the camera's built-in flash firing. Not only do they add more light to the scene, they can also be pointed in any direction to bounce the light off a wall or ceiling to soften it and reduce dark shadows.
- If your subjects have red eyes, turn on the camera's redeye reduction mode that fires a preflash to close down their irises before firing the main flash to take the picture.
The Metz Mecablitz 28 CS-2 fires when it senses the built-in flash firing and can he handheld off camera for more interesting lighting effects. Prior to its first use, the slave has to be adapted to the technology of the flash unit built into the camera to find out if it works with or without preflashes. There are instructions in the manual on how to do this.