Smartphone Photography Quiz

Computational photography uses software algorithms running on the device to perform tasks that would require complex hardware in a traditional camera: multi-frame noise reduction, focus stacking, exposure blending, and scene analysis all happen automatically after the shutter is pressed.

HDR mode on a phone captures several frames at different exposures and merges them automatically, keeping detail in both a bright sky and a dark foreground. Stabilization reduces blur, digital zoom crops, and burst mode captures sequences; none of them extends dynamic range.

Optical zoom changes the actual focal length of the lens, maintaining the full pixel resolution of the sensor across the magnified view. Digital zoom simply crops and enlarges the central portion of the sensor's image, which reduces effective resolution just as cropping a file does.

When the screen is tapped, the phone focuses on that point and also meters exposure from it, so brightness adjusts to the chosen subject. Many phones offer a long press to lock both together. White balance usually stays on auto, and focal length does not change.

Portrait mode uses depth information from extra lenses or software to separate the subject from the background, then blurs the background. It imitates the shallow depth of field and bokeh of a larger sensor with a wide aperture, which a phone's small sensor cannot produce optically at normal distances.

Tapping the touchscreen transfers a small but perceptible vibration into the phone at the moment of capture. A physical button press or remote trigger fires the shutter without that contact, producing sharper images especially in low light or at slow shutter speeds.

Night mode captures several frames at different exposures over a short period and combines them computationally: aligned frames are averaged to reduce noise while the merged result retains far more detail and dynamic range than a single long exposure could produce handheld.

RAW or DNG saves the sensor data before the phone applies its processing, with far more tonal and color information than JPEG or HEIC. That allows larger changes to white balance, exposure, and shadows without banding or artifacts. JPEG and HEIC are already processed and compressed, and GIF is limited to 256 colors.

Grid lines divide the screen into thirds, which makes it easy to place a subject on a third and to keep the horizon level. They are a framing aid only and have nothing to do with focus, color accuracy, or battery life.

A phone's wide or ultrawide lens has a very short focal length and is usually used close to subjects. Nearby objects look much larger than distant ones, and straight lines near the edges stretch or bend. Compressing the background is what long lenses appear to do.