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Science-Related Homework Help Physics Topic started by: dovewing3 on Feb 28, 2012



Title: For what distance should the camera lens be focused?
Post by: dovewing3 on Feb 28, 2012
Suppose that you want to take a photograph of yourself as you look at your image in a flat mirror 2.4  away. For what distance should the camera lens be focused?


Title: Re: For what distance should the camera lens be focused?
Post by: shraddhanand on Feb 28, 2012
Here's a hint: The image in a plane mirror is the same distance behind the mirror as the object is in front of the mirror.


Title: Re: For what distance should the camera lens be focused?
Post by: js11w on Feb 28, 2012
So, you want your photograph of yourself in the mirror. In other words you want the photograph of the image produced on the mirror. Your image in the mirror would be 4.8m away from you and therefore the camera must be focused for 4.8m right?


Title: Re: For what distance should the camera lens be focused?
Post by: Halie on Feb 28, 2012
this depends on the f number of the camera lens. you'll see this as, for example, an f/1.4 camera lens.

once you know this, then you can use the lens makers formula to determine where the camera can be placed to focus the image correctly.


Title: Re: For what distance should the camera lens be focused?
Post by: George on Feb 28, 2012
Solutions are posted, it's double the distance, enjoy!