If a CCD could record 80% of the photons striking it, and a photograph 4%, how m
ID: 287825 • Letter: I
Question
If a CCD could record 80% of the photons striking it, and a photograph 4%, how many times larger in diameter would a telescope have to be to take a photo equal in sensitivity to a CCD image in the same amount of time?If a CCD could record 80% of the photons striking it, and a photograph 4%, how many times larger in diameter would a telescope have to be to take a photo equal in sensitivity to a CCD image in the same amount of time? If a CCD could record 80% of the photons striking it, and a photograph 4%, how many times larger in diameter would a telescope have to be to take a photo equal in sensitivity to a CCD image in the same amount of time?
Explanation / Answer
ANSWER :
4.47 times larger in diameter would a telescope have to be to take a photo equal in sensitivity to a CCD image in the same amount of time.
EXPLANATION:
Photograph captures 1/20 of the photons which CCD captures, therefore its telescope need 20 times of the area.
Objective lens/mirrors area of the telescope is calculated from area
Area= (R²)
So the diameter of the photographs telescope is 20 = 4.47