PH1 Digital Photography Glossary of Basic Terms.docx

Courseware on Multimedia NITTTR Bhopal
DEPARTMENT OF ELECTRONIC MEDIA Page 1
A Brief Handout on Photography
This Handout is divided in four sections:
Section -1 Characteristics of Good Photographs
Section-2- Digital Photography Glossary of Basic Terms
Section -2- How digital camera works?
Section -3 Factors affecting quality of a digital camera
Section -1 Characteristics of Good Photographs
Composition and Lightiing
 Although rules are made to be broken in the art world, good photographs have usually been
composed with one of a few classic art techniques in mind.
The rule of thirds is a common guideline.
Selection of proper camera settings as per light available: Day light or artificial.
 Storytelling
After looking at a photograph you may feel that you understand a situation more completely, feel
the emotion of the event or want to take action based on what you've seen.

 Emotion
Instant sighs, gasps or wide-eyed reactions to a photograph are a good thing. This instant
moment of emotion means the photograph can elicit a response from its viewer. This is a good,
and desired, photographic quality in advertising, marketing and sales photography.
 Vision
Photographers strive to show everyday things in a new and inventive way. Having creative
vision makes a photograph good in the eyes of both the photographer and the viewer, according

to author Darren Rowse at The Digital Photography School. Rowse says the ability to find
beauty in anything creates a great photographer and photograph.
 Moment
Fleeting moments in time that last for a mere second can be preserved forever by a photograph.
A good photograph of these moments will capture the exact moment emotion is released and
facial expressions tell the rest of the story.
Section-2 Glossary of Basic Terms in Digital Photography
The Digital Photography Glossary shared by Microsoft Windows XP as a basic learning on the
terms used in enhancing our common communication language in the world of photography.
Digital camera – A camera that captures the photo not on film, but in an electronic imaging
sensor that takes the place of film.

CCD – Charge Coupled Device: one of the two main types of image sensors used in digital
cameras. When a picture is taken, the CCD is struck by light coming through the camera's lens.
Each of the thousands or millions of tiny pixels that make up the CCD convert this light into
electrons.
The number of electrons, usually described as the pixel's accumulated charge, is measured,
then converted to a digital value. This last step occurs outside the CCD, in a camera component
called an analog-to-digital converter.
CMOS – Complementary Metal-Oxide Semiconductor: one of the two main types of image
sensors used in digital cameras. Its basic function is the same as that of a CCD. CMOS sensors
are currently found in only a handful of digital cameras.
Aperture – A small, circular opening inside the lens that can change in diameter to control the
amount of light reaching the camera's sensor as a picture is taken. The aperture diameter is
expressed in f-stops; the lower the number, the larger the aperture.
For instance, the aperture opening when set to f/2.8 is larger than at f/8. The aperture and
shutter speed together control the total amount of light reaching the sensor. A larger aperture
passes more light through to the sensor. Many cameras have an aperture priority mode that
allows you to adjust the aperture to your own liking. See also shutter speed.
ISO speed – A rating of a film's sensitivity to light. Though digital cameras don't use film, they
have adopted the same rating system for describing the sensitivity of the camera's imaging
sensor.
Digital cameras often include a control for adjusting the ISO speed; some will adjust it
automatically depending on the lighting conditions, adjusting it upwards as the available light
dims. Generally, as ISO speed climbs, image quality drops.
RGB – Red, Green, Blue: the three colors to which the human visual system, digital cameras
and many other devices are sensitive.
Saturation – How rich the colors are in a photo.
Sensitivity – See ISO speed.
Sharpness – The clarity of detail in a photo.
Shutter speed – The camera's shutter speed is a measurement of how long its shutter remains
open as the picture is taken. The slower the shutter speed, the longer the exposure time. When
the shutter speed is set to 1/125 or simply 125, this means that the shutter will be open for
exactly 1/125th of one second.
The shutter speed and aperture together control the total amount of light reaching the sensor.
Some digital cameras have a shutter priority mode that allows you to set the shutter speed to
your liking. See also aperture.
Ambient light – The natural light in a scene.
Pixel – Picture Element: digital photographs are comprised of thousands or millions of them;
they are the building blocks of a digital photo.
Image resolution - The number of pixels in a digital photo is commonly referred to as its image
resolution.
Grayscale – A photo made up of varying tones
CompactFlash™ – A common type of digital camera memory card, about the size of a
matchbook. There are two types of cards, Type I and Type II. They vary only in their thickness,
with Type I being slightly thinner.

A CompactFlash memory card can contain either flash memory or a miniature hard drive. The
flash memory type is more prevalent.
Contrast – The difference between the darkest and lightest areas in a photo. The greater the
difference, the higher the contrast.
Red-eye – The red glow from a subject's eyes caused by light from a flash reflecting off the
blood vessels behind the retina in the eye. The effect is most common when light levels are low,
outdoor at night, or indoor in a dimly-lit room.
White balance – A function on the camera to compensate for different colors of light being
emitted by different light sources.
Panning – A photography technique in which the camera follows a moving subject. Done
correctly, the subject is sharp and clear, while the background is blurred, giving a sense of
motion to the photo.
Fill flash – A flash technique used to brighten deep shadow areas, typically outdoors on sunny
days. Some digital cameras include a fill flash mode that forces the flash to fire, even in bright
light.
Fire – Slang for shooting a picture. Example: I pressed the shutter button to fire.
of black and white. Grayscale is synonymous with black and white.
Highlights – The brightest parts of a photo.
Buffer – Memory in the camera that stores digital photos before they are written to the memory
card.
RAW – The RAW image format is the data as it comes directly off the CCD, with no in-camera
processing is performed.
JPEG – A standard for compressing image data developed by the Joint Photographic Experts
Group, hence the name JPEG. Strictly speaking, JPEG is not a file format, it's a compression
method that is used within a file format, such as the EXIF-JPEG format common to digital
cameras.
It is referred to as a lossy format, which means some quality is lost in achieving JPEG's high
compression rates. Usually, if a high-quality, low-compression JPEG setting is chosen on a
digital camera, the loss of quality is not detectable to the eye.
EXIF – Exchangeable Image File: the file format used by most digital cameras. For example,
when a typical camera is set to record a JPEG, it's actually recording an EXIF file that uses
JPEG compression to compress the photo data within the file.
External flash – A supplementary flash unit that connects to the camera with a cable, or is
triggered by the light from the camera's internal flash. Many fun and creative effects can be
created with external flash.
LCD – Liquid Crystal Display: a low-power monitor often used on the top and/or rear of a digital
camera to display settings or the photo itself.
Media – Material that information is written to and stored on. Digital photography storage media
includes CompactFlash cards and CDs.
Megabyte (MB) – A measurement of data storage equal to 1024 kilobytes (KB).
Megapixel – Equal to one million pixels.

FireWire – A type of cabling technology for transferring data to and from digital devices at high
speed. Some professional digital cameras and memory card readers connect to the computer
over FireWire.
FireWire card readers are typically faster than those that connect via USB. Also known as IEEE
1394, FireWire was invented by Apple Computer but is now commonly used with Windows-
based PCs as well.
Download, downloading – The process of moving computer data from one location to another.
Though the term is normally used to describe the transfer, or downloading, of data from the
Internet, it is also used to describe the transfer of photos from a camera memory card to the
computer. Example: I downloaded photos to my PC.
DPI – Dots per inch: A measurement of the resolution of a print form digital photo including
printers. The higher the number, the greater the resolution.
NiMH – Nickel Metal-Hydride: a type of rechargeable battery that can be recharged many times.
NiMH batteries provide sufficient power to run digital cameras and flashes.
Histogram – A graphic representation of the range of tones from dark to light in a photo. Some
digital cameras include a histogram feature that enables a precise check on the exposure of the
photo.
Image browser – An application that enables you to view digital photos. Some browsers also
allow you to rename files, convert photos from one file format to another, add text descriptions,
and more.
Image editor – A computer program that enables you to adjust a photo to improve its
appearance. With image editing software, you can darken or lighten a photo, rotate it, adjust its
contrast, crop out extraneous detail, remove red-eye and more.
Dodging – Selectively lightening part of a photo with an image editing program.
Online photo printer – A company that receives digital photos uploaded to its Web site, prints
them, then sends the prints back by mail or courier.
Inkjet – A printer that places ink on the paper by spraying droplets through tiny nozzles.
Application – A computer program, such as an image editor or image browser.
Archival – The ability of a material, including some printing papers and compact discs, to last
for many years.
CD-R – CD-Recordable: a compact disc that holds either 650 or 700 MB of digital information,
including digital photos. Creating one is commonly referred to as burning a CD. A CD-R disc
can only be written to once, and is an ideal storage medium for original digital photos.
CD-RW – CD-Rewritable: similar in virtually all respects to a CD-R, except that a CD-RW disc
can be written and erased many times. This makes them best suited to many backup tasks, but
not for long term storage of original digital photos.
CMYK – Cyan, Magenta, Yellow, Black. The four colors in the inksets of many photo-quality
printers. Some printers use six ink colors to achieve smoother, more photographic prints. The
two additional colors are often lighter shades of cyan and magenta.
Memory Stick®—A memory card slightly smaller than a single stick of chewing gum. Like
CompactFlash and SmartMedia, it is flash-based storage for your photos.
Serial – A method for connecting an external device such as a printer, scanner, or camera, to a
computer. It has been all but replaced by USB and FireWire in modern computers.

SmartMedia™ - a wafer-thin, matchbook size memory card. This is also a flash-memory based
storage medium.
Thumbnail – A small version of a photo. Image browsers commonly display thumbnails of
photos several or even dozens at a time. In Windows XP's My Pictures, you can view
thumbnails of photos in both the Thumbnails and Filmstrip view modes.
USB – Universal Serial Bus: a protocol for transferring data to and from digital devices. Many
digital cameras and memory card readers connect to the USB port on a computer. USB card
readers are typically faster than cameras or readers that connect to the serial port, but slower
than those that connect via FireWire.
Section -3 How digital camera works?
When you take a picture with a digital camera the light strikes a digital sensor array, instead of a
piece of film. These digital sensors are computer "chips" with names like CCD, CMOS, Foveon,
or others. They take the place of a piece of film that must be moved across the focal plane of
the camera. The digital sensor is made of millions of tiny sensor points called "pixels," which is
short for "picture elements." They are laid out in an array with rows and columns, like in a
computer spreadsheet or wall calendar. For instance, my camera has an array of sensors in its
CCD that is 3008 horizontally, and 2000 pixels vertically (3008x2000).
The biggest difference in the operation of the camera is in the storage medium, and number of
images made between changes. For instance, with a 35mm camera, you can have a maximum
of about 36 exposures before you have to rewind the film, open the back, and insert another film
roll. With digital you might be able to shoot hundreds of images before changing your "digital
film". Most digital cameras use a small memory card that inserts into a slot in the camera body.
Usually it will be behind a small door on the side or bottom of the camera. The camera manual
will explain the process well enough to get started.
what is a megapixel?
If you do a simple mathematical formula on the pixel array size you will come up with the
"Megapixel" rating of the camera. This is the number that most manufacturers use to sell the
camera. The simple formula 3008x2000 = 6,016,000 shows that my camera has over six million
pixels, or is a "six megapixel" camera.
We can think of megapixels as millions of dots of light that
are being stored for each picture. The more dots of light there
are, the higher the resolution of the image. More pixel dots =
bigger pictures. Usually, the more megapixels the better! It
takes a lot of megapixels to make prints on photo paper, so it
would be best to get a camera with as many megapixels as
you can afford.
..
When the image strikes the sensor, it gets all those megapixels excited. First the image goes
through color filters above the individual sensors. The sensor converts the image from light
waves into an analog electrical signal. The analog signal is then run through an analog to digital
converter (A-D Converter), where it becomes a pure digital signal. Then it is again put through a
series of electronic filters that adjust the white balance, color, and aliasing of the image. Next a

compression cycle makes the image as small as possible by dumping unnecessary pixels, for
more efficient storage. Now the camera has a nice compressed, filtered, digital signal
representing your image.
The image is then transferred into a temporary storage area inside the camera called "buffer
memory," or simply the "buffer." When the buffer is full, the image is written out to your storage
media, such as a memory card. The buffer size in the camera is an important thing. It tells how
many images you can take in quick succession. If you have a tiny buffer in your camera, you will
have to wait a bit after you take several images.
In fact, the main thing that drives the cost up on digital cameras is the number of megapixels,
and the size of the memory buffer. Most cameras have a reasonable amount of both, so you
needn't worry. Even if you can only afford a very inexpensive digital camera, you will still have
nice images, you just might be limited in their maximum size on photo paper, and will have to
wait a bit when taking images quickly. Almost any digital camera is capable of taking pictures for
display on the Internet, or for sending across the Internet as email. Images on the Internet are
very low resolution -- about 72 to 100 dots per inch -- so any quality digital camera will be
capable of making beautiful images for display there.
Section -4 Factors Affecting Quality Of A Digital Camera
The quality of a digital camera is mainly defined by four quantities: resolution, lens aperture,
lens zoom range, lens quality, and software. CCD sensitivity also varies somewhat.
Resolution
Nearly all digital cameras use CCD's as the sensing element. This is what takes the place of
film. The resolution is the number of pixels in the captured image. Computer images are divided
into little dots called pixels. The more pixels, the more detailed the image can be. Here is a
guide to choosing resolution, estimating the size print you can make from each:
 1.3 Megapixel = 1280x960: Great 4x6's, acceptable 5x7's.
 2 Megapixel = 1600x1200: Pretty good 8x10's.
 3 Megapixel = 2048x1536: Great 8x10's, good 11x14's.
 4 Megapixel = 2272 x 1704: Great 11x14's, and acceptable 16x20's.
 5 Megapixel = 2560x1920: Pretty good 16x20's.
 6 - 10 Megapixels = At this point you are usually limited by the lens, not the pixels.
Casual photographers are satisfied with bigger prints from each size, while those who like to
look at 8x10's from a distance of three inches think I am being too generous in the above
evaluations.
Lens aperture
The aperture of a lens is its maximum opening. The bigger the aperture, the more light is
gathered, and the less light you need to take a good photo. This is the most overlooked lens
specification, but it very important, especially if you like to take photos indoors without flash or
from a reasonable distance.

Lens aperture is measured in f/numbers, such as f/2.0 or f/3.5. An aperture of f/2.0 literally
means that the lens opening is half the focal length of the lens. Thus, smaller numbers mean
bigger lens openings. You would rather have a lens that is f/2.0 than a lens that is f/4.0.
Its good to have a fast (large aperture) lens. It means you can shoot photos indoors without
flash, and these look a lot more natural than flash photos. You can also take a lot of photos less
obtrusively without a flash. Digital photographers tend to shoot a lot of photos,
So, what is a good aperture? The answer is getting worse, not better. Do not buy a camera with
a slower lens than f/2.8. These days, you will have trouble finding a non-SLR camera with an
f/1.8 lens. The best seems to be f/2.8 - f/3.5.
Note that cameras with zoom often have a range of maximum apertures listed, such as f/2.5 -
f/4.0. This means the maximum aperture at the most wide angle setting is f/2.5, and the
maximum aperture at the most telephoto setting is f/4.0.
Lens zoom range
A zoom lens has a variable focal length. The focal length determines the magnification of the
lens. A short focal length is a wide-angle lens, great for taking in large vistas. A long focal length
is a telephoto lens, allowing you to get a tight photo of a distant object or person. A zoom lens
lets you combine both of these and everything in between into a single adjustable lens. If a
camera has a 3X zoom, it means that the longest focal length is 3 times the shortest.
The subsequent discussion is using 35-mm equivalent focal lengths.
Most digital cameras have a 3X zoom, with a focal length range from around 35 mm to 105 mm.
35 mm is a modest wide angle, and 105 mm is a modest telephoto. Superzoom cameras have
extreme zoom ranges of 8X or 10X. These generally have about the same minimum focal length
of around 35mm, but these usually have a much longer maximum focal length. Digital SLR's
almost always have interchangeable lenses that allow you to pick whatever focal length you
want.
Long focal lengths mean you can get a tight photo of your children's faces, or a shot on the
soccer field where you child is actually recognizable. Extreme focal lengths let you get in real
close to the action even from the sidelines of a soccer field.
(Important: Ignore "digital zoom" specifications in ads. Only pay attention to optical
zoom. Digital zoom is of no value. All it does is crop the image in the camera. You can always
crop an image in software after you have transferred it to your computer, and you have more
freedom at this time.)
Long focal lengths present problems for photographers. It is hard to hold a camera sufficiently
stable at a focal length of 300 mm. Bright sunlight helps, and a tripod or monopod can do
wonders. An increasing number of cameras with extreme zooms have stabilized lenses that
compensate for camera shake. Good stabilization can make a remarkable difference in
sharpness of handheld shots at extreme focal lengths. Do not buy a superzoom without image
stabilization unless you plan on using a tripod.

Lens quality
Lenses with the same focal length and aperture can differ substantially in quality. A poor lens is
not as sharp, and it may exhibit chromatic aberration, which means that all colors are not
brought to the same focus. This usually shows up as colored fringes at high contrast edges.
Unlike aperture and zoom range, you cannot read the lens quality of the camera box. The two
best approaches to getting a good lens are (1) read reviews, and (2) stick with reputable camera
companies. I tend to trust camera companies such as Olympus, Nikon, and Canon more than
electronics companies who only moved into cameras with the advent of digital photography. It is
easier of a camera manufacturer to incorporate good electronics than for a camera company to
incorporate good optics. A few of the electronics companies are buying optics from reputable
lens companies.
In-camera Software
This is about photo software that comes with your computer, but rather the software built into
the camera. Taking a digital photo means a fair amount of computation. When you snap a digital
photo, the camera first grabs a "pre-photo" to determine the brightness and color balance of the
scene. It then shoots the real picture, based on the earlier information.
This is an important calculation. The importance of brightness is obvious. Less obvious is how
radically the colors of different light sources are. Slide photographers no this. If you shoot
standard "daylight" film indoors under incandescent lights, everything is orange. Film
photographers see less of a problem, because the processing labs that print our photos correct
for most of these color shifts. With digital photography, you want the camera to do all of this
color compensation for you. This is not easy, since the camera needs to distinguish between
incandescent illumination and a daylight scene with a lot of red and orange colors.
Media type
Most digital cameras use CompactFlash or Secure Digital (SD). The difference is not worth
worrying about unless you already have a good supply of one type. Many Sony cameras use
their own proprietary "memory sticks". Avoid proprietary solutions, as it restricts your future
choices considerably. The trend is toward SD (Secure Digital).
Secure Digital or (SD) is a non-volatile memory card format for use in portable devices, such
as mobile phones, digital cameras, GPS navigation devices, and tablet computers. The Secure
Digital standard is maintained by the SD Card Association (SDA)
Types of cards
The SDA extended the SD specification in various ways:
 It defined electrically identical cards in smaller sizes: miniSD and microSD (originally
named TransFlash or TF). Smaller cards are usable in larger slots through use of a
passive adapter. By comparison, Reduced Size MultiMediaCards (RS-MMCs) are simply
shorter MMCs and can be used in MMC slots by use of a physical extender.

 It defined higher-capacity cards, some with faster speeds and added capabilities: SDHC
(Secure Digital High Capacity) and SDXC (Secure Digital eXtended Capacity). These
cards redefine the interface so that they cannot be used in older host devices.
 It defined an SDIO card family that provides input-output functions and may also provide
memory functions. These cards are only fully functional in host devices designed to
support their input-output functions.
Physical size
 Size comparison of families: SD, miniSD, microSD
 The SD card specification defines three physical sizes. The SD and SDHC families are
available in all three sizes, but the SDXC family is not available in the mini size, and the
SDIO family is not available in the micro size.
Memory capacity
The Secure Digital High Capacity (SDHC) format, defined in Version 2.0 of the SD
specification, supports cards with capacities up to 32 GB. The SDHC trademark is
licensed to ensure compatibility.
Fig. Different Types of Cards
References
http://www.wfu.edu/~matthews/misc/DigPhotog/start/camera.html
http://www.nikonians.org/html/resources/guides/digital/how_does_it_work_1.html
http://www.astropix.com/HTML/I_ASTROP/HOW.HTM
http://www.ehow.com

http://en.wikipedia.org/wiki/Photography
-----------------------------------------------------------------------------
Practice sessions: Study of Camera features
Taking shots in Day light, indoor, Different resolutions, Four pictures of trainee’s choice
Shri. Suresh Dixit , Cameraman
Shri. A.L.Vishwakarma, Photographer
Shri. R.K.Shukla Assistant Photographer

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