Auto Exposure Bracketing (AEB)

canon40d

Yesterday we talked about the Fill Flash Technique, as a useful tool in tricky lighting conditions. Today well talk about another technique called Auto Exposure Bracketing (AEB). So what exactly is Auto Exposure Bracketing? Autobracketing is a feature found on more advanced cameras, mostly, DSLR cameras, but I have seen Autobracketing starting to show up even in some of the high-end point and shoots.

Simply put, AEB is where the camera will automatically take several successive shots (usually a series of three) with slightly different exposure settings. Depending on your cameras AEB settings, the difference between each of the autobracketed shots could be anywhere up to two stops in each direction, in half-stop or one-third stop increments.

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The reason you do this is because the camera might have been deceived by the light (too much or too little) available and your main subject may be over- or under-exposed. By taking three differently exposed shots, you are making sure that if this were ever the case, then you would have properly compensated for it.

As an example, say you are taking a scene where there is an abundance of light around your main subject (for example, at the beach on a sunny day, or surrounded by snow). In this case, using Weighted-Average metering, your camera might be 'deceived' by the abundance of light and expose for it by closing down the aperture and/or using a faster shuter speed, with the result that the main subject might be under-exposed. By taking an extra shot at a slight over-exposure, you would in fact be over-exposing the surroundings, but properly exposing the main subject.

Anytime your photographing a subject with tricky lighting or lots of variation between bright and darker areas. Anytime you feel the scene is a challenging one (too much highlights or shadows).  For example, sunrise/sunsets are usually better taken slightly under-exposed so using Auto Exposure Bracketing (AEB) here is a great idea.

To sum things up, be sure and use AEB whenever you want to be sure you don't improperly expose a fabulous shot that you may not get the chance to go back and take again. Use AEB whenever you want to be absolutely sure you have the best exposure possible.

Multi-point vs Single Point AF

Today's cameras provide fast, reliable, auto focus systems (AF). Most modern cameras are now equipped with multi-point AF sensors that do a great job provide quick high-speed tracking for our subjects. As great as the technology is, it can't read your mind. Even the most advance auto focus system cannot determine your photographic intentions. With subjects at various distances from the camera, a multi-point AF system will often focus on the nearest reliable target. Undoubtedly there will be times the cameras auto focus will focus on the wrong subject, giving you less than desirable results.

Instead of relying on your cameras auto focus to make decisions for you. Why not break away from the point-and-shoot approach, and tell the camera exactly where you want the focus.

Most cameras today, that offer multi-point AF, allow you to manually select which focus point to use to ensure focus on your intended subject, and give your photos the results you want.

I recommend setting your camera to use a single focus point. In my opinion, using the method of Focus and Compose, is the most effective method of getting accurate shots.

To use this method, simply set your cameras AF to only use the center focus point. The rest is strictly technique. When taking a picture, position the camera's center AF point directly on the subject you wish to be focused on, then activate your cameras AF Lock by pressing the shutter button down halfway. Once your cameras signals you a focus lock, (usually a audio beep or the center AF point in the view finder will light up). Continue to hold the shutter down halfway, then recompose your shot.

We've all seen those fantastic portraits were the models eyes just draw you in. In these type of portrait shots, we generally want to focus on the eyes. This effect can rarely be achieved in a point-and-shoot mode with multi-point AF.

Using the Focus and Recompose Method, we simply place the center AF point directly on the subjects eyes, lock the focus, and recompose, once composed, take the shot.

This will take some practice, but the results are well worth it.