Assignment 2 for Phot 121: Depth of Field

This Assignment is to illustrate the effects of the aperture on your image. 

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 film 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:

 Part A: Shoot at least one roll of film showcasing a shallow depth-of-field

 Part B: Shoot at least one roll of film showcasing a deep depth-of-field

Due on 2/27/19 are all the proof sheets and two 8x10 enlargements. One 8x10 print with a shallow depth-of-field image, and one 8x10 print with a deep depth-of-field images. 

Below is a chart to help illustrate apertures and depth of field and also fast and slow shutter speeds.