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usn7564
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Homework Statement
Surgeons often use a type of "binocular microscope" [that's a word by word translation]. It consists of a 50mm lens close to the patient and a -15mm right in front of the doctor's eye.
The distance between the patient and the 50 mm lens is 400mm and the negative lens is placed so that the image and object have the same distance from the doctor's eye (for correct depth perception).
What should the distance between the lenses be?
Homework Equations
[tex]\frac{1}{f} = \frac{1}{s} + \frac{1}{s'}[/tex]
The Attempt at a Solution
I know how to solve, quite easily in fact. The mathematics isn't mind boggling but where I'm having trouble is visualizing it. I assumed it would work like a regular microscope because of no reason but "I don't know how it would work with a negative rather than positive eyepiece".
I sat trying to ray trace it to come to some conclusion of my own but didn't get anywhere. Can't wrap my head around how to go about it when there's a lens system with a negative lens.
This is where I'd like some help, my thinking (probably faulty) was that something like this could occur. Is this way off the realm of actual physics?
http://img163.imageshack.us/img163/3164/j51b.png
In any case, without just know the fact that the image from the lens closest to the patient should be between the two lenses and works as an object for the second lens how do I deduce it?
Thank you
Edit: Changed img tags to not mess with forum layout
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