Stops
A one-stop difference is a factor of two in light. A scene spanning many stops may exceed what the sensor can record between its noise floor and highlight clipping in one exposure.
Can one exposure hold the sky and foreground?
Move scene contrast, usable sensor dynamic range and exposure placement. The model shows why a bright Moon, twilight horizon or artificial light can clip long before the stars and foreground are recorded cleanly.
Interactive capture window
Shadow excess—
Highlight excess—
Physical fact vs model
Scene dynamic range is the brightness span between the darkest and brightest relevant detail. A sensor has finite usable range, but its exact value is not a fixed universal number. This visualization centers EV ranges only to teach clipping trade-offs.
In the field
Use the RAW histogram and highlight warnings. Protect irreplaceable highlights such as the Moon or bright twilight, then check whether foreground shadows can be lifted without unacceptable noise. Bracketing is often safer when the scene exceeds one capture.
Try it
Set scene contrast to 15 EV and sensor range to 11 EV. Move exposure placement left and right: you can trade highlight headroom for shadow headroom, but you cannot fit a 15 EV scene into an 11 EV window with exposure compensation alone.
Common mistake
Do not treat the rear-screen JPEG histogram as identical to RAW headroom, and do not assume a published sensor DR number remains the same at every ISO.
Related
What dynamic range means in a real scene
Exposure placement
Moving exposure brighter lifts shadows above noise but pushes highlights toward clipping. Moving darker protects highlights but may leave foreground information too close to the noise floor.
Not all clipping is equal
A tiny specular reflection or solar disc may be allowed to clip while cloud texture or illuminated architecture must be preserved. Decide which tones contain important recoverable detail.
Field workflow
Watch the RGB histogram and highlight warnings, not only the preview. If important shadows and highlights cannot coexist, bracket exposures, use a graduated filter when appropriate, or change shooting time.