Question: How far away from my subject can I be and still fill the photo frame (top-to-bottom) with an image of the subject?

Height of Object: | meters |

Focal length of the lens: | millimeters |

Vertical size of image sensor: | millimeters |

Answer: The maximum distance from the subject you can be is 0.0 meters.

Question: I am doing macro photography (close-ups). At a certain distance, what percent of my image sensor (top-to-bottom) will the subject I am photographing occupy?

Height of Object: | meters |

Focal length of the lens: | millimeters |

Distance between you and the oject: | meters |

Vertical size of image sensor: | millimeters |

Answer: At a distance of 0.0 meters, the subject will occupy 0% of your image sensor (or 0.00mm). The magnification factor will be 0.0, meaning the lens must have a macro ratio (or maximum magnification) of 1:0 or better in order to focus at this distance.

For those who are curious, the formulas used for these two calculations are shown below:

where

d_{o} = maximum distance from the object

h_{o} = height of the object being photographed

h_{s} = height of the camera image sensor

f = the focal length of the lens.

where

p = percent of the image sensor that will be occupied by the object being photographed.

d_{o} = maximum distance from the object

h_{o} = height of the object being photographed

h_{s} = height of the camera image sensor

f = the focal length of the lens.