Advanced Exposure Quiz: ETTR, Stops & Manual Mode Decisions

Opening the aperture one stop doubles the light, so one stop has to come off somewhere else. A shutter speed one stop faster halves the light again and keeps the exposure the same. Raising the ISO or opening the aperture further would make the picture brighter still.

Exposing to the right means making the exposure as bright as possible while keeping the highlights just short of clipping, so the histogram sits toward the right edge. The extra light improves the signal in the shadows and lowers noise once the image is brought back to normal brightness in editing. It does not mean underexposing or centering the histogram.

A RAW file often holds a little more highlight data than the camera's preview or histogram shows, and if only one color channel has clipped the software can rebuild detail from the others. Once all channels are fully clipped, though, nothing remains to recover. So recovery depends on how much headroom was left.

Halving the shutter time halves the light reaching the sensor, which is a reduction of one stop. Each stop represents a factor of two: doubling or halving the shutter speed, aperture area, or ISO each shifts exposure by exactly one stop.

Exposing to the right pushes brightness up to gather more shadow data, but often requires a slower shutter speed or wider aperture to do so. A slower shutter introduces motion blur risk, which can outweigh the noise benefit in scenes with movement.

Negative exposure compensation tells the camera to make the image darker than the meter suggests, which pulls bright areas back from clipping. Positive compensation, a higher ISO or a wider aperture all add brightness and push highlights closer to white.

Exposure compensation shifts the brightness the meter aims for, for example one stop brighter or darker than its middle gray target. In aperture priority your chosen aperture stays fixed; the camera reaches the new target by changing shutter speed, or ISO when Auto ISO is on.

Stage lighting puts bright faces against a mostly black background, so an evaluative meter sees all that darkness and overexposes the performer. Spot metering on the lit skin, then keeping the brightest highlights from clipping, exposes for the part of the scene that matters.

A flash pulse is far shorter than any shutter speed at or below sync speed, so the flash fires completely while the shutter is open whether that is 1/60 or 1/200 second. Changing the shutter speed therefore changes the ambient light and motion blur but not the flash exposure.

Each stop of ISO doubles the brightness, so two stops is 2 x 2: four times the exposure. Doubling would be only one stop.

At high ISO there is less highlight headroom, so bright areas clip easily. Exposing slightly darker keeps highlight detail, at the price of a bit more noise when the shadows are lifted later. It does not reduce noise or add dynamic range.

A stop is a doubling or halving of the light that makes the exposure. It applies to all three settings: one stop of shutter speed (1/250 to 1/125), aperture (f/8 to f/5.6) or ISO (200 to 400) each doubles or halves the light.

A high contrast scene contains both very bright and very dark areas, so its tones pile up near both ends of the histogram with less in the middle. A single central spike is what a flat, low contrast scene looks like.

Closing the aperture two stops cuts the light to a quarter. With ISO fixed, the shutter has to stay open four times as long, which is two stops slower, to bring the exposure back. A faster shutter would cut the light even further.

Dynamic range is set by the sensor's ability to hold highlights before clipping and its noise floor in the shadows. Raising ISO reduces highlight headroom, so dynamic range is largest at base ISO and shrinks as ISO goes up. Focal length and AF mode have no effect, and file format alone cannot add range the sensor never recorded.