Deviprasad Goenka Management college of Media Studies http://www.dgmcms.org.in/ Subject:Photography Lesson 1:Types of Lens , Mega Pixel , Image Quality . Faculty Name: Partha Pratim Samanta

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Lesson # 3
Types of Lens , Mega Pixel , Image Quality .
Subject:
Photography
Faculty Name:
Partha Pratim
Samanta
FY BA
India’s premier Media -school
Deviprasad Goenka Management College of Media Studies (dgmcms.org.in)

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Lens
A camera lens is an optical lens used in conjunction with a camera
body and mechanism to make images of objects either on photographic
film or on other media capable of storing an image chemically or
electronically.

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How Lens Work
A lens gathers the rays of light coming from a scene and projects
them as reversed images onto the film at the back of the camera. You
can see this demonstrated below:

4. + Types of Lens
 Normal Lens
 Tele Photo Lens
 Wide Angle lens

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Types of Lens
The telephoto on the other hand allows the
photographer to capture light from greater
distances and make it appear to be closer than
the scene really is.
Finally the wide-angle does the opposite of the
telephoto lens, it make the scene seem farther
away and expands the viewable area.

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Types of Lens
When a photographer speaks of the speed of his or her lens, they
are simply referring to the measure of light that transmits through
the lens to the film.
A larger aperture lens allows more light than a small aperture
lens. This diameter is measured as an f-stop.

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Types of Lens
EF-S zoom- EF- S 10-18mm, EF- S 10-22 mm, EF- S 15-85mm, EF- S 17-
55mm, EF- S 17-85mm, EF- S 18-55mm, EF- S 18-135mm, EF- S 18-200mm,
EF- S 55-250mm
Ultra Wide Zoom EF-S 10–18mm, EF 16–35mm, EF-S 10–22mm,
EF 17–40mm, EF-S 15–85mm.
Standard Zoom- EF-S 17–55mm, EF 24–70mm, EF-S 17–85mm,
EF 24–105mm, EF-S 18–55mm, EF 28–135mm, EF-S 18–135mm,
EF 28–300mm, EF-S 18–200mm.
Telephoto- EF-S 55–250mm, EF 70–200mm.
Standard Prime EF 70–300mm EF 40mm, EF 100–400mm,
EF 50mm, EF 200–400mm.

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Types of Lens
Telephoto Prime Wide Angle Prime EF 85mm, EF 14mm,
EF 100mm, EF 20mm, EF 135mm, EF 24mm, EF 200mm, EF
28mm.
Super telephoto Prime EF 35mm, EF 300mm.
Macro EF 400mm , EF 50mm.

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Zoom Lenses & Prime Lenses
 A zoom lens is one where the photographer can vary the focal
length within a pre-defined range, whereas this cannot be
changed with a "prime" or fixed focal length lens. The primary
advantage of a zoom lens is that it is easier to achieve a variety
of compositions or perspectives (since lens changes are not
necessary). This advantage is often critical for dynamic subject
matter, such as in photojournalism and children's photography.
 An inexpensive prime lens can generally provide as good (or
better) image quality as a high-end zoom lens.

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Pixels & Megapixel
Digital cameras capture images as pixel
elements, known as pixels.
Note :- Simply put, a megapixel is equal to one
million pixels.
EXAMPLE :- 1 dot = 1 pixel
8 dot = byte Pixel
1024 dots = Kilo Pixel
AND
1048576 dots = Mega Pixel
And so on.

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Elements of picture quality
The number of megapixels is only one aspect relating to the quality of a
camera
or
Factors such as camera sensor and processor, and the optical quality
of a lens, play equally important roles.
Other elements determine the quality of photos and prints. They
include:
 Good lighting of a subject
 Proper focus and exposure
 Image clarity (lack of blur due to camera shake or incorrect shutter
speed)
 Shooting at the highest resolution and quality camera settings

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F-Length
The aperture range of a lens refers to the amount that the lens can
open up or close down to let in more or less light,
respectively. Apertures are listed in terms of f-numbers, which
quantitatively describe relative light-gathering area (depicted below).
Note: Above comparison is qualitative; aperture opening (iris) is rarely a
perfect circle, due to the presence of 5-8 blade-like lens diaphragms.
That larger aperture openings are defined to have lower f-numbers
(often very confusing).

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Depth of Field
The depth of field (DOF) is the portion of a scene that appears
sharp in the image. Although a lens can precisely focus at only one
distance, the decrease in sharpness is gradual on either side of the
focused distance, so that within the DOF, the unsharpness is
imperceptible under normal viewing conditions.

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Depth of Field

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Take Away Tips
Many cameras use interchangeable lenses.
When a photographer speaks of the speed of his or her lens, they are simply
referring to the measure of light that transmits through the lens to the film.
 Think
 Experiment
 Move
 Wait
 Rule of Thirds