Take the 2-minute tour ×
Physics Stack Exchange is a question and answer site for active researchers, academics and students of physics. It's 100% free, no registration required.

I'm given with these data:

Lens 1 and lens 2 are convex lenses with different focal lengths

Distance of object from lens 1: 50 mm
Distance between lens 1 and lens 2: 100 mm
Distance of final image from lens 1: 300 mm

How to compute for the Distance of first image from lens 1? A ray diagram for this kind of set-up will be appreciated. Thank you!

share|improve this question

1 Answer 1

up vote 1 down vote accepted

You just use the lens formula:

$$ \frac{1}{u} + \frac{1}{v} = \frac{1}{f} $$

Do the calculation for the first lens to find the position of the image, then do the calculation for the second lens taking $u$ to the distance of the first image from the second lens. Make $u$ negative if the image is on the far side of the second lens.

share|improve this answer

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.