Description of the Unit – This is the second lesson of a seven-lesson photography unit, and for this lesson we are focused on aperture, and its effect on exposure and depth of field.
To see lesson one, click here: https://anitasagastegui.com/2020/08/14/8th-grade-photography-unit-lesson-1-composition-and-intro-to-your-camera-settings/
Activity statement – I would venture to say that aperture, shutter speed and ISO are the most important settings on your camera. Know how each one works, and how each affects an image, and the rest is icing on the cake.
Aperture is the opening of your lens. This opening can range from very small to very wide, and therefore determines the amount of light that can enter your camera. Imagine your pupil dilating, form small to large. It is widest when it is darkest, to let in more light. Well, your camera works in a similar way. Most camera’s apertures range from f/2.8 to f/29, but many can go lower than 2.8 and higher than 29. We call these “f-stops”. An f-stop, or aperture, of 1.8 is a very wide opening, while an f-stop, or aperture, of f/29 is quite small. While this may seem counter intuitive to some, I tell my students to imagine these numbers as fractions, and thus a fraction of 1/1.8 is larger than 1/29.
One way the aperture setting affects an image is through exposure. It’s like Goldilocks and the three bears. If your aperture is opened too wide, your image will be overexposed. If the aperture is too narrow, the image will be underexposed. With the correct aperture, your image comes out just right. Continuously practicing, and even playing with some bracketing exercises, (in which you take the same image several times under different apertures), helps one tremendously. So, the best students can do to improve their skills is to have their cameras with them as much as possible and to shoot, shoot, shoot. If possible, students should take notes on the settings used so they can reference them when viewing the images later.
Of course, using the shutter speed setting in tandem with aperture is key, but that’s for a later lesson. For now, it is important for students to know how to change the aperture setting on their cameras, and to understand why they would want to.
Depth of Field – Besides affecting exposure, aperture also affects depth of field. Depth of field is the distance between the closest and furthest objects within an image that appear relatively sharp. During class I do my best to explain the physics involved (some of my students do a better job with this than I do!), but the objective here is for students to understand that the lower your aperture (meaning the wider the opening) the more shallow the depth of field. A shallow depth of field means the subject is mostly the only things properly in focus. The higher your aperture (meaning the smaller the opening), the deeper your depth of field, which means that along with your subject, most of the foreground and background is also in focus. Give students time to discuss when one might want a shallow depth of field, and when one might want a larger one, all while observing examples of each.
Photographer Spotlight – This week’s featured photographer is Nuri Bilge Ceylan. Ceylan is mostly known for his award-winning films, however I also find his photography fascinating, and his 2007 series For my Father has beautiful examples of both shallow and large depth of fields, along with being just breathtaking photos.
The homework for this lesson is for students to turn in at least one example of an image with shallow depth of field. If students can turn in the image along with the settings used, it makes the learning experience all the more useful. As usual, we reinforce what we learned in this lesson with an off-campus photo walk.
Goals – Students should…
- How aperture affects exposure
- How aperture affects depth-of-field
- Concretely what aperture is
- How to change the aperture on their camera
Be able to:
- Adjust the aperture setting to take a shot with a shallow depth of field
- Adjust the aperture setting to take a shot with a large depth of field
Resources and materials –
- A digital camera that can has a shutter speed, aperture and manual setting
- A memory card with enough space for the day’s photo excursion
- Fully charged battery
- Examples of photos highlighting the day’s lesson (composition in this case)
- One or two photographer’s works that emphasize the day’s lesson
- Student discussion
- Answers to essential questions
- Student images focused on aperture and depth of field (to be critiqued the following week)
Student images with APERTURE and DEPTH OF FIELD as focus