Bracketing and HDR - PowerPoint Presentation

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Bracketing and HDRSlide2

Bracketing

Is the technique

of taking several shots of the same subject using different aperture, shutter speed or ISO settingsWhy do you think you would want to use this? Is useful and often recommended in situations that make it difficult to obtain a satisfactory image with a single shot. Maybe you want to take a picture like the one to the right. The rocks require one exposure, the water another, and the sky yet another.Gives the photo a HDR look (HIGH DYNAMIC RANGE)Slide3

How do you do it?

You bracket by taking one overexposed, one properly exposed, and one underexposed picture of

exactly the same subject, camera must be in the same position. So 3 pictures total.What do you think you might need to do this?What if your subject is moving?Good news, your camera has a bracketing button. So the camera will take these 3 pictures for you with just one click of the shutter.We are going to practice doing it ourselves by adjusting the aperture, shutter speed, and ISO.Then we will learn the bracketing function on your camera.Slide4

1/125th, f~5.6, ISO 100

1/125th,

f~8,

ISO 100

1/125th, f~11, ISO 100

Exposure bracketing-

one stop darker and one stop lighter, changing the

aperture

only. Keep the shutter speed the SAME.

Proper exposure

Underexposed

Overexposed

Hands on!! Try it on your camera. Slide5

Exposure bracketing-

one stop lighter and one stop darker, changing the shutter speed ONLY

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Which one of these is proper exposure? Overexposed? Underexposed?

f/16 @ 1/60 of a second

f/16 @ 1/125 of a second

f/16 @ 1/250 of a second

Hands on!! Try it on your camera. Slide6

Exposure bracketing-

one stop lighter and one stop darker,

changing the ISO ONLY.HANDS ON. TRY IT.Slide7

Exposure bracketing-

one stop lighter and one stop darker,

using the camera’s bracketing button.HANDS ON. TRY IT.Slide8

What now?

So now that you have your 3 images, you can blend them together in

Photoshop or Photomatix to create an HDR picture.HDR stands for High Dynamic Range and it’s purpose is to take an image where there are extreme lights and extreme darks and properly blend the two together to create an image with a high dynamic range!Slide9

High Dynamic Range

A camera is capable of capturing a limited amount of tones in a single photo (we call

between pure black and pure white). Typically we sacrifice elements in a photo when we set the cameras exposure. We meter for the most important part of the scene. For example let's look at the series of images.

The center image is a typical exposure, showing an average metering to produce the most detail possible. Notice that the detail outside the door is lost because it's too bright. Also the detail on the stair rail is lost because it's too dark. When you are at the location, you are able to see all these detail with your eye, this is because the human eye can see a larger range of tones than the camera can capture on the sensor or film in a single photograph.Slide10

f/16 1/320 sec.

Overexposed

f/16 1/640 sec. Properly exposed

f/16 1/800 sec.

UnderexposedSlide11
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Black and White HDR photosSlide16

When not to use HDR

Photos with Movement

 (see above): If any of your subjects are moving (or might move), HDR increases the chance of a blurry photo. Remember, HDR takes three pictures, so if your subject moves between the first and second shot, your final picture won't look very good. Photo by William Hook.Vivid Colors: If your scene is too dark or too light, HDR can bring some of the color back. However, if you're dealing with colors that are already very vivid, HDR can wash them out.HDR with people in the image looks bad too. It often gives people a “halo”Slide17

What to do today.

Go

out and practice bracketingPractice merging your bracketing photos and creating an HDR image using Photomatix