Photo 120: Assignment 2 Depth of Field

When light passes through your lens, it’s funneled (so to speak) through the lens via the aperture. When the light passes through a lens with a wide open (F/2.8 for example), it scatters across the sensor plane in a circular fashion. So, areas that the lens is not focused on will appear blurry due to the light not being funneled through the lens in a linear fashion. (For techies out there, this area of out of focus on the sensor plane is called the circle of confusion). Because of this effect of the lens and aperture, when you have a point of focus with lots of areas around that point being blurry, we describe that as an image with shallow depth-of-field.

As we stop our aperture down (making it a smaller diameter), the light is funneled into the camera in a more linear fashion and the circles of confusion are smaller. As this occurs, more items around point of focus will appear sharper. This effect continues as we stop our lens down further and further (down to f/11 and continuing to f/22). With these smaller apertures, we will gain more and more areas of focus. Another way to describe this is to have an image with a long or deep depth-of-field.

Other factors that effect depth-of-field are the focal length of the lens, and the distance you are to the subject. Lenses with a longer focal length will inherently have a shallower depth of field while shorter focal length lenses will have a longer depth-of-field.

 Another factor is your own camera distance to the subject. As you move in closer to the subject, the depth-of-field will decrease. This is because as you move in closer, the ratio between you and the subject, and the subject and the background changes. In other words, as you get closer to your subject, your image will have a blurrier background even when using the same aperture. 

Due for this assignment are the following:

Shallow Depth of Field
Make a minimum of 5 images illustrating shallow depth-of-field

Deep Depth of Field
Make a minimum of 5 more images (different from any of the previous images) illustrating a deep depth-of-field. 

Comparing Deep and Shallow Depth of Field 
Photograph a minimum of five different scenes with both a shallow and deep depth-of-fields. Between the two images, you should clearly see a difference in the area of focus when you take the first “shallow” image and the second “deep” image. Make sure that the focus is on the same spot on both images. Also make sure that the exposure between the two image are similar (equivalent). 10 images are due for this last part of the assignment.

Students will export a Smart Catalog with three different collections showcasing the different parts of the assignment: Shallow, Deep and Side by side. 20 images due in total.

 This assignment is due 9/18/19