What is pincushion effect?

Related questions

1. Why are stars so big?
2. Can telescope see through clouds?
3. How long would it take to travel 4 light years?
4. How many years is a light year?
5. What's the coldest star in the universe?
6. Are there clouds on Saturn?
7. Why do astronomers use adaptive optics?
8. Why do astronomers use telescopes?
9. What is plate height?
10. What does distortion mean in photography?

Tags

1. #distance
2. #distortion
3. #pincushion
4. #through
5. #increases
6. #visible
7. #inwards
8. #bowed
9. #magnification
10. #centre
11. #effect
12. #image
13. #optical
14. #towards
15. #lines