Transcript Document

How does a camera work?
Ksenia Bykova
Types of film cameras
 SLR
cameras (Single Lens Reflex) – you see
the actual real image
 “Point-and-shoot”
cameras – you don’t see
the real image formed by the camera lens,
but you have an idea of what is in view.
Three basic elements of a film
camera

An optical element (the lens)

A chemical element (the film)

A mechanical element (the camera body itself)
The most important part of camera is the lens. Let’s discuss it in more
detail.
What is lens?

“A lens is an optical device which affects the focusing of a light beam
through refraction” ("Lens (optics)." Wikipedia. Wikimedia Foundation, 18 Nov. 2014. Web.
17 Nov. 2014.)

A simple lens consists of a single piece of material, while a compound
lens consists of several simple lenses (elements).

Lenses are made from glass that is ground and polished to a desired
shape.
The focal length
The focal length of a lens is defined as the distance in mm from the optical
center of the lens to the focal point.
The focal length f is then given by
where u is the distance between the light source and the lens, and v is the
distance between the lens and the screen.
The magnification
Magnification is the ratio of the image size to the object size. The
greater the focal length, the higher the magnification.
With , being the distance from the lens to the image, the distance from the
lens to the object,
the height of the image and
the height of the object,
the magnification can be written as:
Convex Vs. Concave lenses
Convex lens
Concave lens
A convex lens makes objects look
farther away
A Concave lens makes objects look
smaller and closer
A convex lens is thicker in the middle
than it is at its edges
A concave lens is thicker at the edges
than it is at the center
A convex lens refracts light rays inward
A concave lens refracts light rays,
spreading them outward
Types of lenses

Wide-angle lenses

Normal lenses

Long-focus lenses

Telephoto lenses

Prime lenses

Macro lenses

Zoom lenses
Wide-angle lenses
Wide-angle lenses have huge, 60+ degree angles of view, and
are usually used for focusing on objects closer to the
photographer. Usually wide-angle lenses have short focal
lengths.
Normal lenses
Normal lenses are those that most closely represent
the “natural” imaging similar to what the human
eye captures. These are typically between 35mm
and 50mm
Long-focus lenses
Long-focus lenses are the huge lenses that are used to
magnify objects at great distances. They have the narrowest
angle of view, and are often used to create depth of field
shots and shots where background images are blurred.
Telephoto lenses
Telephoto lens - an optically compressed version of the long-focus lens.
Telephoto lenses are typically much shorter and may be lighter for
equivalent focal length. Telephoto lenses have longer corresponding focal
lengths.
Prime lenses
A prime lens has no zoom – it is one focal length.
The lens is manufactured precisely to provide this
one length, and doesn’t have the moving pieces and
mechanisms required to zoom.
Macro lenses
Macro lenses have an intense level of magnification,
capable of picking out the tiniest details and
enhancing them to be larger than what we can see
with our own eyes
Zoom lenses
A zoom lens allows the photographer to vary the
focal length, whereas this cannot be changed with a
fixed focal length lens.
“A simple zoom lens system. The three lenses of the
afocal system areL1, L2, L3 (from left). L1 and L2 can
move to the left and right, changing the overall focal
length of the system (see image below).” ("Zoom
Lens." Wikipedia. Wikimedia Foundation, 27 Oct. 2014. Web. 21 Nov. 2014. )
How does a film camera work?
“All of these pieces work together to get the final picture:
1. Light reflects off the object being photographed.
2. This light reflects off the object in all different directions and hits the lens from different
angles.
3. The lens focuses these rays of light to a point behind the focal point forming a real image.
4. The film is placed at the point where the real image is projected to.
5. The shutter temporarily moves from in front of the film and allows light to hit the film.
6. Light hits the film causing chemical reactions which "expose" the film.
7. The shutter then closes, and finally the film is advanced so an unexposed piece of film is ready
for the next picture.” ("How Does A Camera Work?" How Does A Camera Work? N.p., n.d. Web.
16 Nov. 2014.)
Film camera Vs. Digital camera
When film is exposed to light, the light can be appropriately dispersed
while minimizing reflection, since the surface of film is not like a mirror.
With digital cameras, however, strong reflection occurs when light falls
on the image sensor.
Personal Insight
I’m very interested in photography and cameras. Personally,
this topic is very important for me, because I want to work
in the film and media industry. Thanks to this project I
discovered a lot of interesting and useful information which
helps me understand how a camera works. For example, I
learned different focal lengths and angels of view. In
addition, I learned many new types of lenses in cameras.
Sources

"HTG Explains: Cameras, Lenses, and How Photography Works." HowTo Geek RSS. N.p., n.d. Web. 18 Nov.
2014. http://www.howtogeek.com/63409/htg-explains-cameras-lenses-and-how-photography-works/

"How Does A Camera Work?" How Does A Camera Work? N.p., n.d. Web. 18 Nov. 2014.
http://www.leydenscience.org/physics/electmag/camera2.htm

"SLR Cameras vs. Point-and-Shoot - HowStuffWorks." HowStuffWorks. N.p., n.d. Web. 18 Nov. 2014.
http://electronics.howstuffworks.com/camera5.htm

"Lens (optics)." Wikipedia. Wikimedia Foundation, 18 Nov. 2014. Web. 18 Nov. 2014.
http://en.wikipedia.org/wiki/Lens_(optics)

"What Are Concave and Convex Lenses? Part 2." Research the Topic -. N.p., n.d. Web. 18 Nov. 2014.
http://researchthetopic.wikispaces.com/What+are+concave+and+convex+lenses%3F+Part+2

"UNDERSTANDING CAMERA LENSES." Understanding Camera Lenses. N.p., n.d. Web. 18 Nov. 2014.
http://www.cambridgeincolour.com/tutorials/camera-lenses.htm

"Types of Camera Lenses." PictureCorrect RSS. N.p., n.d. Web. 18 Nov. 2014.
http://www.picturecorrect.com/tips/types-of-camera-lenses/

"Focal Length." Wikipedia. Wikimedia Foundation, 18 Nov. 2014. Web. 21 Nov. 2014.
http://en.wikipedia.org/wiki/Focal_length

"Magnification." Wikipedia. Wikimedia Foundation, 20 Nov. 2014. Web. 21 Nov. 2014.
http://en.wikipedia.org/wiki/Magnification

"Zoom Lens." Wikipedia. Wikimedia Foundation, 27 Oct. 2014. Web. 21 Nov. 2014.
http://en.wikipedia.org/wiki/Zoom_lens
Picture citations

http://en.wikipedia.org/wiki/Lens_(optics)#mediaviewer/File:Lens_and_wavefronts.gif

http://www.dcresource.com/forums/showthread.php?29937-Fuji-Wide-Angle-Lens

http://www.photographymad.com/pages/view/wide-angle-lenses

http://www.lelong.com.my/3-1-fisheye-wideangle-macro-handphone-special-effect-lens-sebastiantai-1445445072014-04-Sale-P.htm

http://en.wikipedia.org/wiki/Long-focus_lens

http://commons.wikimedia.org/wiki/File:Canon_telephoto_lens.jpg

http://en.wikipedia.org/wiki/Prime_lens#mediaviewer/File:Pentacon_electric_f2,8_29mm_MC_lens.jpg

http://www.topdesignmag.com/macro-lens-photography/

http://www.uwphotographyguide.com/olympus-60mm-macro-lens-review

http://en.wikipedia.org/wiki/Normal_lens#mediaviewer/File:Normal_Lenses_7253.jpg

http://www.davidreneke.com/binoculars-for-astronomy/

http://www.artandstructure.com/photography/artofpho/widetele.php
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http://www.nikonusa.com/en/Learn-And-Explore/Article/g3cu6o2o/understanding-focallength.html#!/media:image:red-barn-sequence.jpg
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http://sachinb.blogspot.com/2010_11_01_archive.html
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http://en.wikipedia.org/wiki/Macro_photography#mediaviewer/File:Close-up.png
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http://en.wikipedia.org/wiki/Wide-angle_lens#mediaviewer/File:Lens_wideangle.svg
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http://en.wikipedia.org/wiki/Photographic_lens_design#mediaviewer/File:Tessar.png