(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

An object at a distance a_{1}in front of a convex lens with the focal length f_{1}is imaged at a distance b_{1}. A second lens at the distance d from the first lens with the focal length f_{2}is then imaging this Image with the image distance b_{2}.

a) Give the image distance b_{1}as a function of f_{1}and a_{1}, as well as the image distance b_{2}as function of d, a_{1}, f_{1}and f_{2}.

b) What is the focal length of a System of two lenses which distance d approaches zero?

c) Which focal length must the second lens in b) have to compensate the action of the first lens? How is such a lens called?

2. Relevant equations

Lens equations, f_{s}=(f_{1}*f_{2})/(f_{1}+f_{2}).

3. The attempt at a solution

For b) I have found the equation given above. How can I figure out c)? I think it is anafocal system, is that correct? For that, the focal length must be f_{2}=d-f_{1}?

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# Homework Help: A system of two lenses

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