When using a digital SLR camera to take starry sky photography, the factor that has the greatest impact on the quality is ( ) A. Sensitivity B. Exposure time C. Aperture D. Focus adjustment

Exposure time.

Because photographing the starry sky requires a long exposure, it is necessary to accurately grasp the specific exposure time. However, it is also inseparable from the set sensitivity (the higher the sensitivity, the shorter the exposure time) and the aperture size (the higher the aperture, the shorter the exposure time).

Exposure time is the time the shutter needs to be open in order to project light onto the photosensitive surface of the photographic photosensitive material. It depends on the sensitivity of the photographic photosensitive material and the illumination on the photosensitive surface. The longer the exposure time, the more light will enter, which is suitable for situations where the light conditions are poor. A short exposure time is suitable for situations where the light is relatively good.

Extended information

During this period of time, the object can leave an image on the film. The exposure time depends on the need. There is no long or short term, only good or bad term. .

For example, if you take a picture of the trajectory of stars, you need a long exposure time (perhaps several hours), so that the long-term trajectory of the stars will be imaged on the film. If you want to take a clear shot of a speeding car, it takes a very short time (usually a few thousandths of a second). The longer the exposure time, the more light will enter, which is suitable for situations where the light conditions are poor. A short exposure time is suitable for situations where the light is relatively good.