{"id":31180,"date":"2017-03-27T07:00:32","date_gmt":"2017-03-27T11:00:32","guid":{"rendered":"https:\/\/www.adorama.com\/alc\/?p=31180"},"modified":"2022-07-20T10:45:02","modified_gmt":"2022-07-20T14:45:02","slug":"getting-a-better-understanding-on-exposure","status":"publish","type":"post","link":"https:\/\/www.adorama.com\/alc\/getting-a-better-understanding-on-exposure\/","title":{"rendered":"Understanding Exposure"},"content":{"rendered":"

One of the goals in photography is to obtain the correct exposure when capturing an image. Mastering this can really take a lot of practice, but the great thing about digital cameras these days is that it doesn\u2019t cost you anything extra to test for proper exposure – as much as you need to for getting it down. <\/span><\/p>\n

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Example of correct exposure. Orchid at the NY Botanical Gardens.<\/em><\/p>\n

Shot at ISO 250, F\/4.5 at 1\/50 of a sec.<\/em><\/p>\n

So what is exposure? The technical definition of exposure is that it is a process by which light that reflects off of a subject hits the camera sensor through an opening in the camera lens (aperture) for a specific duration (shutter speed). The sensitivity of the sensor (ISO) determines how large the lens opening should be and how long the light can pass through. The proper combination of these three factors results in a properly exposed image and is often referred to as the Exposure Triangle.<\/span><\/p>\n

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Correct exposure just after sunset as twilight has a cooler hue.<\/em><\/p>\n

Top of Arc du Triomphe in Paris, France<\/em><\/p>\n

The Exposure Triangle<\/b><\/h3>\n

The Exposure Triangle is made up of aperture, shutter speed and ISO, as exhibited in the detailed diagram below. Let\u2019s discuss now what each of these elements specifically are and what they do.<\/span><\/p>\n

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The Exposure Triangle.<\/em><\/p>\n

Image courtesy of Google.<\/em><\/p>\n

Aperture<\/b><\/h3>\n

As I mentioned before, aperture is basically how large the opening of the lens is when a picture is taken. The aperture is what controls the amount of light that enters the camera. The smaller the opening (the higher the number), the less light will come into the camera. The larger the opening (the lower the number), the more light will come into the camera.<\/span><\/p>\n

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I created this aperture diagram as an easier way of understanding aperture.<\/em><\/p>\n

When Aperture Priority is Best Used<\/b><\/p>\n

Aperture Priority is best when you are wanting to control the Depth of Field<\/a>. When shooting things like landscapes, cityscapes and seascapes, you will most likely want everything sharp in focus, so you will need the maximum aperture (a higher number). When you are photographing people, whether it\u2019s portraits or headshots, you will most likely want your subject to be the only thing in focus with things behind your subject out of focus so as to avoid mergers and distractions in the portrait or headshot.<\/span><\/p>\n

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Shooting with the focus on aperture allowed me to create a shallow depth of field, blurring the background behind my subject.<\/em><\/p>\n

ISO 200. Shot at F\/2.5 at 1\/50 of a sec.<\/em><\/p>\n

Model\/Actress: Valery Lessard<\/em><\/p>\n

Shutter Speed<\/b><\/h3>\n

Shutter speed<\/a> can best be described as the amount of time that the shutter stays open when a picture is taken. The longer you leave the shutter open, the more light that gets onto the sensor. This is a good setting for when you are trying to capture motion, however, you run the risk of introducing noise\/grain into the image. It\u2019s also a good way to control freezing motion and to make everything in the image sharp.<\/span><\/p>\n

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My simple diagram of what shutter speed is and what it does. <\/em><\/p>\n

The less time the shutter stays open (a slower shutter speed), the less light will hit the image sensor. This is good for when you are trying to freeze motion. You are less likely to get noise\/grain into your image when using a fast shutter speed.<\/span><\/p>\n

When Shutter Priority is Best Used<\/b><\/p>\n