Question

Which of the following best describes the principle advantage of CCDs over photographic film?

A) CCDs allow long exposures (e.g., minutes or hours) and film does not.
B) CCDs capture a much higher percentage of the incoming photons than film.
C) CCDs can record the colors of astronomical objects accurately while film cannot.
D) CCDs can be attached to modern telescopes more easily than can photographic film.

Answer 1

The main advantage of CCDs over photographic film is their efficiency in capturing photons, with some exceeding 90% sensitivity, allowing for the detection of fainter objects and providing precise brightness measurements.

Step-by-step explanation:

The question asks about the principal advantage of CCDs (charge-coupled devices) over photographic film in the context of astronomy. The best answer to this question is B) CCDs capture a much higher percentage of the incoming photons than film. While traditional photographic films are quite inefficient, capturing only about 1% of the light that falls on them, CCDs are much more sensitive. They can record around 60-70% of the photons, with the best achieving over 90% sensitivity. This high efficiency allows astronomers to detect much fainter objects and also provides digital output that can be easily analyzed using a computer. In addition, CCDs offer more accurate measurements of the brightness of astronomical objects compared to photography.