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Author Topic: Distance from subject question  (Read 613 times)


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Distance from subject question
« on: April 11, 2013, 09:38:00 AM »
I'm having a senior moment here and need a formula.
I want to take a mirror image of a church steeple using 24x48 piece of black acrylic as the mirror...let's assume that the steeple is 200 ft tall.
How far from the steeple do I place the mirror to fill that mirror with the I said, just need the distance/size relationship formula.   Thanks


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Re: Distance from subject question
« Reply #1 on: April 11, 2013, 10:20:32 AM »
The distance to the mirror will be proportional to the distance to the subject. If you are caputuring a 200ft tall subject in a 2ft or 4ft tall mirror, then the mirror will need to be ~100x or ~50x closer to you than to the subject. The actual distances will depend on your field of view, ie the focal lenth of the lens that you use. So as a rough guide, frame your mirror in the lens that you plan to use and note your distance from the mirror, and then multiply that distance by 100x or 50x to get an approximate distance from the mirror to the subject.
« Last Edit: April 11, 2013, 10:26:08 AM by chriswatters »