Exam-style question
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What is a disadvantage of refracting telescopes compared to reflecting telescopes?.
- A.They are heavier and more difficult to mount.
- B.They suffer from chromatic aberration.
- C.They cannot be used for astrophotography.
- D.They are more expensive to produce.
Model answer
What a good answer should say
- They suffer from chromatic aberration.
Explanation
Why this works
A significant disadvantage of refracting telescopes compared to reflecting telescopes is that they suffer from chromatic aberration. This optical distortion occurs because different wavelengths of light are refracted by different amounts, leading to color fringing in images.
The key difference is the optical element used: lenses in refracting telescopes versus mirrors in reflecting telescopes. This aberration limits the performance of refracting telescopes, especially at larger apertures, making reflecting telescopes a better choice for high-quality astronomical observations.
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