Wolfram|Alpha

Computing...

Input information:

thin lens equation |  \nfocal length | 20 feet\ndistance between object and lens | 400 feet


Result:

distance between image and lens | 6.417 meters\n= 21.05 feet\n= 21\' 0.6316"


Equation:

1\/i + 1\/o = 1\/f |  \ni | distance between image and lens\nf | focal length\no | distance between object and lens


Ray plot:


ComputingComputing...