How thin lens model work when there are two images with different distances from the lens? - Physics Stack Exchange most recent 30 from physics.stackexchange.com 2019-07-20T05:45:33Z https://physics.stackexchange.com/feeds/question/257991 http://www.creativecommons.org/licenses/by-sa/3.0/rdf https://physics.stackexchange.com/q/257991 0 How thin lens model work when there are two images with different distances from the lens? aukxn https://physics.stackexchange.com/users/41974 2016-05-25T21:48:41Z 2018-09-03T15:01:23Z <p>I am trying to understand how thin lens camera work. From what I understand of thins lens model, the image is formed on image plane that obey the equation</p> <p>$$\frac1S_1 + \frac1S_2 = \frac1f$$</p> <p><a href="https://i.stack.imgur.com/j1gPv.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/j1gPv.png" alt="enter image description here"></a></p> <p>So how about the case when there are 2 Object with different sizes and the distances of two object to the lens are difference while the image plane of the camera is fixed. Also, the two objects and the lens don't form a straight line so there is no way that one object hide the other one. Let say object A and B has distance $S_A$ and $S_B$. Suppose that </p> <p>$$\frac1S_A + \frac1S_2 = \frac1f$$</p> <p>So in the case of $S_B$</p> <p>$$\frac1S_B + \frac1S_2 \neq \frac1f$$</p> <p>Then how the image of object B is form on image plane of camera</p> <p>Assume that both object have their distance from the lens greater than focal length. </p> https://physics.stackexchange.com/questions/257991/-/258033#258033 1 Answer by Yuval Weissler for How thin lens model work when there are two images with different distances from the lens? Yuval Weissler https://physics.stackexchange.com/users/71693 2016-05-26T05:29:00Z 2016-05-26T05:29:00Z <p>The equation holds true to all object, no matter their distance from the lens, HOWEVER when f is fixed, and the object are at different distances from the lens, then it follows that if one of the object is forming an image, then the other must not!</p> <p>If you had a lens with fixed focal length, and two object at different distances from it, but now you have a screen you can move closer and further from the lens (instead of a fixed sensor), you would find out that both objects can be imaged by the lens - just at different distances from the lens, according to the equation.</p>