Capturing moments in low-light situations is easy with digital cameras—just raise the ISO. Adjusting the ISO on the fl y is easy; simply press the ISO button on the top of the camera and change the ISO number by using the Main dial (see Chapter 1 for more information). In most lighting situations, you will probably be working with an ISO range of 100–800. But as your available light gets lower, pushing the ISO to extremely high numbers will increase the amount of noise in the image (Figure 7.1).
Another option is to use the fl ash when working in locations with low light, but if your subject is too far away, the fl ash won’t reach them. There may also be situations in which fl ash photography is prohibited or not appropriate.
Using a tripod with a slow shutter speed and low ISO setting is another option when the lights are low, but if your subject is moving too fast, you won’t be able to freeze them in place. Tripods also tend to attract a lot of attention, and they are not allowed in some areas. I fi nd that hauling a tripod around can be cumbersome—if I know that I need one for a specifi c image, it’s not a big deal, but if I’m not sure what I’ll be shooting, I prefer other methods that don’t require as much gear.
So if you fi nd that raising your ISO level above 800 is your only option, you can reduce the amount of noise in the image by turning on the High ISO Speed Noise Reduction feature in the Custom Function Settings menu on your 7D. Keep in mind that you may not always notice noise when viewing your images on the back of your camera, since what you’re seeing is a scaled-down version of the original. Using the zoom features on the back of your camera to preview your shots at 100% will give you a better idea of the amount of noise that higher ISO levels introduce into your images.
TURNING ON HIGH ISO SPEED NOISE REDUCTION
- Press the Menu button and locate the Custom Function screen.
- The ISO Expansion setting is located in the C.Fn II: Image section. Highlight it and press Set (A).
- Use the Quick Control dial to locate the High ISO Speed Noise Reduction section (it’s the second menu item), and then press the Set button.
- Use the Quick Control dial to select the level of noise reduction you would like applied to your images (B). Then press the Set button.
Press the Menu button twice to exit. This noise reduction will be applied to all ISO speeds but will be much more noticeable at higher ISO levels.