week 6 discussion
Please watch the weekly discussion video. Next, respond to the prompt below.
In order for a film camera with a fixed focal length F to focus on anobject located a distance x from the lens, the lens must be a distance yfrom the film. F, y, and x are related as follows:
Now suppose a camera has a lens with focal length F = 65.
- Explain what happens to the distance between the lens and the film as the object moves far away from the lens. When an object far away (x is near infinity), what is the internal distance from the lens and film?
- Consider the opposite. Explain what happens to the distance between the lens and the film as the object moves closer and closer to the lens. Is there a distance from the lens at which you can no longer focus?
- In general, why is it not possible to cross a vertical asymptote?
What is focal length, and how does it work?
In photography, fixed focal length means that the focal length is not adjustable. Focal length determines the magnification and angle of the view of your scene. A longer focal length increases the magnification and decreases the angle of view, while a shorter focal length does the opposite.
With a fixed focal length, photographers are unable to zoom in and out on a particular subject. In order to zoom they would either have to change their distance to the object or change the lens. Not being able to easily zoom in on a subject might seem like a huge disadvantage, but such lenses are credited with being able to produce much higher quality pictures in controlled settings.
While the photographer cannot zoom while using a fixed focal length lens,he can still adjust the focus on the object. When the photographer twists the focusing ring, the location of the lens inside the camera adjusts.This change in distance from the lens to the film inside the camera is governed by a rational equation.
Hint: These websites may help with your understanding of this concept
http://www.paragon-press.com/lens/lenchart.htm
http://www.nikonusa.com/en/learn-and-explore/a/tips-and-techniques/understanding-focal-length.html
https://en.wikiapedia.org/wiki/Focal_length
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