A little in-camera insurance to get that shot.
When I was in Italy on business with the Navy, I got a small amount of time off, and took the opportunity to travel to Rome on a guided tour. Normally, when I am out on photo safari I am on my own and under my own time constraints. During this event, the pace of the tour guide restricted me. I decided to give bracketing a chance. Before, I would have manually adjusted my exposures to get the right look. With bracketing, I was able to make three quick photos and review later. I found this to be very convenient, as it allowed me to concentrate more on composition and positioning.
Except for the most basic entry-level cameras, bracketing is featured. On Nikon and Canon mid level and advanced cameras there is custom function button that’s usual default setting is set to bracket mode. Some Nikon cameras equipped with bracketing capability have dedicated buttons for bracketing indicated by a (BKT) button. On more entry-level cameras that have bracketing mode is a special function that is located in the customization menu. I recommend referring to your owner’s manual to see if your camera has bracketing capability. This article is not about knobology but about technique. We will assume you have bracketing capability. If you don’t, you can simulate manually by adjusting the exposure compensation.
What is bracketing?
Bracketing is the process (either manually or automatically) of taking a series of images of the same shot at various settings. The most common setting variation is exposure bracketing. This is the default setting for cameras capable of bracketing. Bracketing can also be focus bracketing, flash bracketing, white balance bracketing, etc. Bracketing is also a vital step to perform HDR photography.
The most common method of bracketing is exposure bracketing. By setting auto bracketing on the number of shots taken and the amount of exposure compensation for each step is set. Nikon cameras allow exposure steps of up to +/-1 Exposure Values (EV). For Canon it may be set to +/-2EV. The bracket amount can be set from 3-9 shots. For 3 shots there are 1 image at exposure and 1 each at +/-1EV. For 5 shots there are same as 3 plus one each at +/-2EV. This can keep increasing until a set of 9 exposures. Usually, you only need three exposures.
Other Types of Bracketing
In the menu settings, the bracket controls can be changed to bracket flash or white balance. These settings are much more rarely used. Flash bracketing will cycle through series of different flash settings including off. White Balance bracketing is less needed if shooting in RAW format, as white balance information is more controllable in postproduction than JPEG. Another option is focus bracketing. This technique uses varying aperture settings to get different amounts of area of focus.
Another type of focus bracketing is rather than changing the aperture setting, but to change the plane of focus. This is hyper focusing. By digitally combining multiple images with different focus distances a greater area of focus could be achieved. It is very tricky and requires extremely well aligned image stacking in post process. I would not recommend trying it. Stopping down on a lens on a tripod would be a better option.
High Dynamic Range Photography
Another reason to bracket and is currently growing into the most popular reason is to create High Dynamic Range (HDR) images. Normally, a camera has a limited range that it resolves between bright highlights and dark shadows. This is frustrating as our eyes are able to resolve the differences easier and the resulting images from cameras do not correspond to what we perceived when took the photo graph. There are many software applications, including Adobe Photoshop, capable of combining multiple exposure of the same image producing an image with a higher exposure gamut than can normally be produced.
So basically, exposure bracketing is a convenient way to give you some insurance that you will come back with a better exposure for your images. It also can open the possibility to produce images that you normally could never imagine before.