Timeline for Difference between focal point and distance away from object?
Current License: CC BY-SA 3.0
5 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Apr 13, 2016 at 19:18 | comment | added | Alan Marcus | The camera sports a converging lens. Light rays enter the lens and their path is altered. The revised path traces out a cone. The distance from lens to apex of the cone is the focal length. This measurement must be taken when the lens is imaging a far distant object. This object is said to be an infinite distance away (∞ Latin for as far as the eye can see). This happens when the object is about 3000 times the working lens diameter distant. At such a distance, light enters as parallel rays. Objects closer raced out an elongated cone of light. We call the elongated distance the “back focus”. | |
| Apr 13, 2016 at 12:49 | comment | added | Euri Pinhollow | "50 mm between if's focus point and the sensor and 10 ft from focus point to subject." - what is "focus point"? | |
| Apr 13, 2016 at 12:39 | comment | added | Michael C | Focus distance is always measured from the film/sensor. Working distance is the measurement from the physical front point of the lens (which may or may not correspond to the lens' entrance pupil. | |
| Apr 12, 2016 at 18:57 | review | Low quality posts | |||
| Apr 12, 2016 at 19:02 | |||||
| Apr 12, 2016 at 18:34 | history | answered | GeeJay33 | CC BY-SA 3.0 |