Exposure and Metering Flashcards

A photographer is taking a portrait of a person standing in front of a very bright window. To ensure the person's face is correctly exposed and not a silhouette, which metering mode is most suitable?

Answer: Spot Metering

Spot metering is the ideal choice for this high-contrast, backlit scenario. It measures light from a very small, specific area of the frame (the 'spot'), allowing the photographer to meter directly off the subject's face. This ensures the primary subject is properly exposed, while ignoring the much brighter background which would otherwise fool an averaging meter into underexposing the subject.

You are photographing a bright, snowy landscape. Your camera's meter, using an averaging mode, is likely to render the snow as a dull gray. To ensure the snow appears correctly as white, what is the most appropriate adjustment?

Answer: Increase exposure compensation (e.g., to +1 or +2 EV)

Camera light meters are calibrated to expose for 'middle gray' (18% gray). A large, bright scene like snow will trick the meter into thinking the scene is too bright, causing it to underexpose the image to turn the white into gray. By increasing the exposure compensation (+EV), you are manually overriding the meter to let in more light, which correctly renders the snow as white.

A photographer reviews an image's histogram and sees the data is heavily concentrated on the far left edge, with a tall spike against the edge and very little data in the middle or right side. What does this histogram indicate?

Answer: The image is underexposed with clipped shadows (crushed blacks).

A histogram is a graph representing the tonal values of an image, from pure black on the far left to pure white on the far right. When the graph's data is pushed up against the far left edge, it signifies that a large number of pixels in the image are pure black, meaning detail in the darkest areas has been lost. This condition is known as underexposure with 'clipped' or 'crushed' blacks.

A photographer establishes a correct exposure using the settings f/8, 1/125s, and ISO 100. They want to create a shallower depth of field by changing the aperture to f/4. To maintain an equivalent exposure, what must the new shutter speed be (assuming ISO remains 100)?

Answer: 1/500s

Changing the aperture from f/8 to f/4 is a two-stop increase in light (f/8 -> f/5.6 -> f/4). To maintain the same overall exposure, you must compensate by reducing the amount of light by two stops using another setting. Increasing the shutter speed from 1/125s to 1/500s is a two-stop decrease in light (1/125s -> 1/250s -> 1/500s), which perfectly balances the change in aperture.

A photographer changes their camera's ISO from 200 to 1600. By how many 'stops' has the sensor's sensitivity to light been increased?

Answer: Three stops

In photography, a 'stop' refers to a doubling or halving of the amount of light or sensitivity. The progression of full ISO stops is a doubling sequence. Starting from ISO 200, the sequence is: 200 -> 400 (1 stop), 400 -> 800 (2 stops), and 800 -> 1600 (3 stops). Therefore, changing from ISO 200 to 1600 is a three-stop increase.

In which of the following scenarios is using Auto Exposure Bracketing (AEB) most beneficial?

Answer: Photographing a high-contrast landscape at sunrise, with a bright sky and dark foreground.

Auto Exposure Bracketing (AEB) is a function where the camera takes several photos of the same scene at different exposure levels (e.g., normal, underexposed, overexposed). This is most useful in high-contrast situations, like a sunrise or sunset, where the dynamic range of the scene exceeds the camera sensor's ability to capture detail in both the brightest highlights and darkest shadows in a single shot. These bracketed images are often later merged to create a High Dynamic Range (HDR) image.