The Pinhole Camera History

The pinhole camera is one of the earliest cameras used in photography. It is an-odd looking thing because, unlike other cameras, it does not need to use lenses to take pictures. To explain, images are projected into the pinhole camera when light passes through a tiny hole in its box-like frame. According to Wikipedia.com, the small hole of the camera can focus light by directing it through a single point. This article will talk about its illustrious history.
Early Discoveries of The Ancient Greeks
Pinhole camera history in Wikipedia.com says that these simple devices were already used by the Greeks as early as 500 B.C. It was a common belief that people were able to see because the light rays were bouncing from the human eye. Wikipedia.com adds that, later on, they found out that seeing was actually an effect of light rays entering into the eye, rather than bouncing from it. This important realization led to a better understanding of how these work.

Ancient china
Mo Jing, a Mohist philosopher in 5th century-China, was said to have studied and experimented with phenomenona of images projected via a very small hole. Because of this, the Mohist philosopher was able to contribute to the development of the pinhole camera and the Burning Mirrors used by the ancient Mohists. Much of the pinhole camera history revolves around key events in Ancient China. In fact, Wikipedia.com also states that Shen Huo, a Chinese scientist during the Song Dynasty, was able to establish the key geometrical and quantitative concepts vital to the development of the pinhole camera today.
1000 to 1600 A.D.
The 10th century Muslim mathematician Ibn al-haytam is credited for inventing the first modern pinhole camera. Further advancements were made to the camera when the Muslim mathematician realized that a smaller hole produced a more sharper image.
In addition, more ideas and studies were done by the brilliant minds of Gemma Frisuis and Giambattista della Porta. These two published a paper explaining why images projected into the pinhole camera appeared upside down. Lynn Bryant, writing for a video surveillance website, said that the studies made by Gemma Frisuis' of a solar eclipse projected into a dark room was the first documented use of a pinhole camera in history.
1800s and Beyond
Lynn Bryant also says that Sir David Brewster, a Scottish scientist, was the first one to take pictures with the pinhole camera back in the 1850s. Lynn Bryant also says that this simple camera was not regarded as a popular medium of photography, not until the 1960s. It may be owing to the fact that the photographers during the period preferred to take pictures using a conventional camera, as opposed to the pinhole camera.
The pinhole camera history can be traced back to the Ancient Greeks, with advancements contributed by the Ancient Chinese and by brilliant scientists and philosophers in the late 20th century. Its history, like the histories of all things ingenious, is colorful, interesting, and absolutely eventful, and one that never fails to prove how great things can come from a simple idea.

Article By Nahshon Roberts

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History of The Camera

Early cameras of the 16th and 17th century were able to project images onto paper or glass but the study of capturing, processing and printing the images took many more years. Up until the 17th century, scientists believed that light was composed basically of the 'white' that is perceived by the human eye. It took the research done by famous physicist Isaac Newton to discover that light is actually composed of a spectrum of colors. While he made a big contribution to the study of optics (that is at the core of camera advances) with this discovery, Newton did not actually have anything to do with camera development per se.
The early camera that first became a phenomenon was a little more than a pinhole camera and can be traced back to 1558. It was called the Camera Obscura. The Camera Obscura was seen as a drawing tool for a clearer and realistic portrayal of objects. It was in the early 19th century that an invention named the Camera Lucida was introduced by Cambridge scientist William Hyde Wollaston that consisted of an optical device that could help an artist view a distant scene or person or object on a paper surface that he or she was using to draw. In other words the artist gets to view a superimposed image of a subject on paper and this image could be effectively used to attempt to draw, trace or paint it. Both the Camera Obscura and the Camera Lucida provided an image that was temporary, which could not be lastingly captured on to paper for later reference.
Studies however continued well into the 1800's on how to actually capture the image onto material. It was during this time, around 1822 that French researcher Joseph Nicephore Niepce, created the first photograph by using paper that was coated with a chemical. The image would not stay permanently on the paper and would disappear after a short while. Even so, despite the short-lived nature of the image, the concept of photography was born with this experiment and paved the way for further study and development in this field.
Capturing images to retain them longer and permanently became the next big quest for researchers. Another Frenchman Louis-Jacques-Mandé Daguerre partnered with Joseph Nicéphore Niépce in 1829, to develop the process of creating permanent photographs. Joseph Niépce died in 1833 but Daguerre continued with the work and succeeded in 1837 after many long years of experimentation. The process of capturing photographic images that would not fade away, introduced by Daguerre came to be known as the 'daguerreotype'.
The word 'photography' was coined by scientist Sir John F.W. Herschel in 1839 and it is actually is derived from two Greek words 'photos' meaning light and 'graphein' meaning draw.

A slightly more advanced version of the daguerreotype called the Calotype process that makes multiple copies possible using the negative and positive method became available very soon after. In fact, it was during the 1840's that the use of photographic images in advertisements first started and cameras made their mark on the power of visual communication. It was not much later, in the 1850's that photographers first started experimenting with underwater photography of seascapes.
Up until 1850, the process of capturing images was cumbersome requiring upto half an hour of light exposure. The discovery made in 1851 by Frederick Scott Archer was a blessing since the new method termed the Collodion process called for just 2-3 seconds of light exposure to capture an image.
Prior to 1871, photographers went through a development process where they had to coat the plate with wet chemical each and every time and process the image immediately. With the invention the gelatin dry plate silver bromide process by Richard Leach Maddox, negatives did not have to be developed immediately. This was an important discovery since up until then the captured image had to be processed instantly.
Kodak created in 1888 by George Eastman has been a modern day pioneer of sorts in cameras and photography for the masses. George Eastman and the scientists who worked with him at Kodak developed the photographic film in 1889 and made it available in rolls for the mass use of consumers. An important milestone in our entertainment and communication history was the development of transparent roll film by Eastman. This development led to another key invention - the motion picture camera by Thomas Edison's in 1891.
-->Modern Times
During the 20th century the pace of technology development in cameras and photography continued at an accelerated pace much like many other key technology developments. While several key inventions like car, telephone and the gramophone record happened in the later half of the 19th century, it is the last 100 years that saw major developmental work in many areas of communications technology and as well as in other fields - TV, aircrafts, PCs, digital technology, digital cameras, mobile phones, fax machines and the internet, to name a few.
In the case of the camera, the developments simplified the whole process of photography, making it accessible to one and all at affordable prices and the camera industry denizens of our times made it into a mass phenomenon. The first mass use camera became available at the turn of the 20th century and can be traced back to the year 1900. There are hundreds of models of cameras available today both for the amateur as well as the professional and the camera is an important part of any family's repertoire of must have gadgets.
-->20th century chronology in the history of the camera:
1913: 35 mm still-camera created
1927: The flash bulb introduced by General Electric Co. (The concept of camera flash existed much before but was based on the use of a flash light powder that was invented by German researchers)
1935- 1941: Kodak starts marketing Kodachrome film and subsequently launches Kodacolor negative film. Canon released the Hansa Canon in 1936, the first 35mm focal-plane shutter camera.
1948: The concept of the Polaroid camera is introduced in the market. American scientist Edwin Land developed the process for instant photography. Later Polaroid Corporation developed the 'instant color' film around 1963.
1957: Frenchman Jaques Yves Cousteau invented the first waterproof 35mm camera for underwater photography named the Calypso Phot. The actual camera was developed by the Belgian airplane technical designer Jean de Wouters based on the blueprint and suggestions given to him by Cousteau.
1972: The electronic camera that does not require film was created and patented by Texas Instruments. This is however not the same as a digital camera though you don't require film in digital cameras as well. The launch of the digital camera is still many years away.
1975: Kodak's experiments with digital imaging kicked off around the mid seventies but it will take another 20 years before a digital camera for the home consumer market is launched.
1978 - 1980: Asian players like Konica and Sony begin to make their mark. The 'point and shoot' automatic focus camera is launched by Konica while Sony starts talking about the camcorder and demonstrates a prototype.
1981: Sony launches a commercially available electronic still camera. Similar to the 1972 invention by Texas Instruments, the Sony electronic camera came with a mini disc on which images were recorded and stored. The recorded images could be later printed or viewed on a monitor using a reader device.
1985: Digital processing technology makes its entry. Digital imaging and processing is introduced by Pixar.
1986: The camera industry becomes even more consumer focused and taps the fun and travel connotations behind camera usage, with the launch of the concept of the disposable single use cameras. Fuji is credited with the development of this concept.
Also in 1986 - 1987, Kodak started taking giant strides in digital development. Digital means, the photographic image is divided into tiny units of dots or squares known as pixels. Pixels are the programmable units of an image that can be processed by computers. Each image could be made up of millions of pixels. The use of pixels in digital technology allows storing large volumes of pixels to deliver high definition print quality.
1990: Kodak introduces Photo CD's. It is a system of storing photographic images on CD and then viewing them on a computer. With this development the user-friendly approach of the camera industry began to take concrete shape.
1991: Kodak introduces a digital camera targeted at professionals and journalists. Kodak is credited with the invention of a pixel based camera technology known to us as the digital camera. Digital cameras don't use film similar to their predecessor electronic cameras but the storage method is entirely different and the final photograph is of much higher resolution. In a digital camera photos are recorded and stored in digital form. This digital data can be transferred to a computer and processed for printing. Kodak and Canon are well known digital camera manufacturers and there are also several other key brands as well.
1994: The Apple QuickTake camera, a home use digital camera is launched. This is followed by the launch of a clutch of home use digital cameras by Casio, Kodak and others in quick succession during 1995 -'96.
-->The digital era:
The development of digital camera technology is considered to be linked to the development of TV and Video technology. The principles of transmission and recording of audio-visual images using digital electrical impulses finds use in camera imaging as well.
Through the 1990's the developments continued in camera technology, the focus now shifting to the field of digital imaging which is where the future lies. Use-friendly features like software that can download digital images directly from camera onto home computers for storing and sharing on the internet is the new norm in the market place.
The camera, the computer, the software industry and the worldwide web are today irrevocably interlinked to empower the user in experiencing the benefits of camera usage to full potential. The innovation that sparked many an invention in the camera industry found its way into the digital world as well and continued among digital camera manufacturers. During 2001, the Kodak and Microsoft partnership ensured that digital camera manufacturers could use the power of Picture Transfer Protocol (PTP) standard through Windows. The digital photo experience is a key visual driver in the Internet era. Many of Kodak digital camera models with EasyShare capabilities are compatible with Windows XP. The Kodak EasyShare software enables users to transfer digital camera pictures directly from camera to their computers and then print the pictures or even email them.
Manufacturers in a related industry like the printing industry have adapted their products to be in sync with the images created by digital cameras. Cell phone manufacturers have tied up with digital camera manufacturers to develop new age camera phones in recent years. These camera phones can capture images and share the images through the cell phone.
Among the 21st century digital developments are the advanced product offerings from digital cameras manufacturers and these are sure to occupy an important place in the ensuing history of camera development. For instance, the Kodak Professional DCS Pro SLR/c is a high-end digital camera and the Kodak website calls the DCS Pro SLR models the most feature-rich digital cameras on the market. It has an image sensor that can handle 13.89 million pixels and this makes it the highest resolution digital camera available. High resolution determines the sharpness or level of detail in photographic images. This is just a glimpse of the capabilities that digital technology places in a user's hands. Digital camera sales figures for 2003 show that the two key players Kodak and Canon have recorded impressive growth.
-->What does the future holds for camera users?
The features offered by digital cameras can be quite mind-boggling for the average user and pretty exciting for most pros. Four key ongoing camera developments that are likely to further improve the process of photography:
1. Greater resolution from even the simplest, low cost camera models
2. Usage in any type of lighting conditions,
3. Compatibility across a range of software, hardware and image types
4. Rich colors and tone
While the higher-end digital evolution continues, the prices of the simple camera have crashed to such an extent that even children and teens are proud owners of uncomplicated cameras. The camera and photography interest starts young and this creates a truly large audience base for the camera industry.
And throughout history, it is evident that the endeavor of researchers and developers has been to make the camera available to a wide section of society. Without camera technology and photography, the other key developments of cinema and TV would have been delayed and what a boring place the world would have been without TV and films!!

Article By Christopher Haslego

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Digital Photo Imaging Tips and Resources

The advent of digital revolution in photography entailed a lot of promise to professional as well as novice digital photography enthusiasts. This emerging industry not only boosted the advent of a profitable market of cell phones and digital camera but also the confidence of each and everyone in pursuing an interest in artistically capturing life's moments and nature's wonders. The variety of digital photo imaging technologies incorporating in digital photography gave more life to your traditional photographs. Now, the storage, printing, processing sharing, and display of your stock photos go beyond conventional dark rooms and photo albums to offer more possibilities in exploring your chosen art form.
The development of various software, programs, and application services offered for digital photographs basically revolve around all the possible means of enhancement that you can do to make your photographs more realistic. They allow you to manipulate certain aspects of your photo and take control of its aesthetics. With that, digital imaging technologies are developed to allow you to make all the necessary adjustments to your photograph's graphics, display resolution, color depth, and other image editing and enhancement applications.
Your digital images may be used for display, ad campaign, instructional purposes, and logos. Through programs like Adobe illustrator, digital photo imaging technologies may be used to add in graphic shapes, text, and other digital image attributes that will fit the photograph to its intended use. Through digital manipulations, it may be put into albums, animated features, and flash displays along with scripted and programmed sequences. The technique and selection of tools used for digital photo imaging depends in the intended purpose of a particular photo.

Prior to printing, digital photo imaging manipulations can be done to ensure quality final prints. For instance, through sampling, you can have your digital image scanned to determine the necessary adjustments to optimize its resolution and determine the appropriate dots per inch settings. This way, you get the best quality out of your final prints.
In terms of pixels, digital photo imaging software and programs like the image editor may be used to edit, enhance or retain the full resolution needed to ensure quality digital image display or prints, especially when a particular photo is resized, cropped, compressed or re-compressed. If the picture is meant to be displayed, similar digital photo imaging programs can be used to achieve the pixel size that is relative to your target resolution of photo display.
Digital photo imaging and editing applications allow you to artistically stylize and add texture to your photographs. To bring more art to your digital photographs, you may need to do some color mapping, object or text overlays and color adjustments. This section digital photo imaging process mainly involves the use of print art. For instance, if you intend to make black and white prints out of your colored pictures, then you need to make adjustments to put in grayscale attributes into your photograph. This digital photo imaging and manipulation technique ranges from incorporating simple graphics to full color compression.
Over the next decades, you shall see the digital photo imaging industry to introduce more dynamic range of tools and editing applications to make excellent digital image output. With these excellent photo color, size, and print calibration, it would be easier to produce clean, crisp, and real-like image out of your raw photographs.

Article By Michael Greenway

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What Is The Best Digital Camera Brand?

If ever there was a controversial question amongst the hordes of digital camera enthusiasts, it has to be "What is the best digital camera brand?". Sometimes referred to as "What is the best brand of digital camera to buy?", but not to be confused with "What is the best camera to buy?". Because everyone knows that regular (film) cameras are far superior to digital cameras. Hang on a sec, or was that the other way around? Who can keep track these days? Now before I digress too far from the topic, lets take a look at that age old battle, and see if we can determine which brand is best.
First things first, in the spirit of full disclosure, I need to declare that I do in fact own several cameras. They represent a variety of brands. I have two Canons, a Fuji, and a Kodak. I must confess, that I am somewhat partial to Canon, but I'll try not to let that cloud any editorial comments I may subsequently make.

If digital camera sales were any indication of what the best brand was, then according to Amazon.com Canon would be a clear winner. As I write this, Canon manufactures 18 of the top 25 bestselling cameras on their best seller list. In addition, Canon holds 9 of the top 10 spots, with the top 3 being the PowerShot A570 IS, the PowerShot SD1000 Digital Elph, and the PowerShot SD850. Sharing the top 11 spots with Canon are 2 of the Pure Video manufactured Flip Video cameras. Nikon has 2 cameras in the top 25 including the Nikon D40, and the Nikon D300. Panasonic sneaks in with a couple of their Lumix models, specifically the DMC-TZ3K and the DMC-TZ3A. And finishing in a strong 25th spot, that old stalwart Kodak with the Easyshare Z812IS.
Of course being popular, or the best seller does not the best brand make. It simply means you have the best salesmanship. In that world, Canon seems to be having the most success. How exactly would we determine the best brand? Best service, best design, best features, best customer support, best images, and best user experience are all valid traits. Perhaps a critical / scientific /empirical examination of all cameras models by manufacturer would be in order. Let's see if we can aggregate a lot of the work already done by a couple of camera review sites who take the above traits into consideration.
A perusal of one top camera review site under their 5 star category, show 39 Canon cameras, 18 Sony cameras, 17 Nikon cameras, 6 Fuji cameras, 5 Olympus cameras, 5 Panasonic cameras, 3 Pentax cameras, and 1 Konica camera. A second camera review site under their top 103 cameras showed 46 Canon cameras, 21 Sony cameras, 20 Nikon cameras, 5 Pentax cameras, 3 Fuji cameras, 2 Samsung cameras, 2 Panasonic cameras, 2 Kodak cameras, 1 Konica camera, and 1 Casio camera. If you total all that up, the top 3 end up being Canon with 85, Sony a distant second with 39, and Nikon a very close third with 37. Everyone else had less than 10 top rated cameras.

Article By Chris Campbell

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Little Knowledge

In 1888, George Eastman began promoting the first hand-held Kodak
camera with the slogan, “You press the button, we do the rest.” His idea
was to make the film camera as convenient as the pencil. However, the film
king’s dream didn’t really come true until the invention of the digital
camera.
Certainly, conventional photography has long been as
simple as pressing a button, but the “we do the rest”
part — taking the film to a photo lab, deciding what
size and kind of prints to make, and then waiting for
the results — is a lot less convenient than using a
pencil.
Digital photography has finally put the entire
process of making pictures in the hands of the
person holding the camera. You press the button,
and you can do as much of the rest yourself as
you’re comfortable with. If all you want to do is point
and shoot, you can do that. If you want to get more
involved in the picture-taking and picture-making process,
digital photography gives you the tools for that, too.
You compose the picture through the viewfinder (as always), but now, you
can preview the exact photograph that you’re going to take on a bright LCD
(liquid crystal display) screen on the back of your camera. After snapping a
shot, you can instantly review the photos you’ve taken and erase the bad
pictures on the spot or “mark” the ones you want to print.

You don’t need to remember to stop and buy film. Your digital film is almost
infinitely reusable. You don’t have to drop off your digital film for finishing:
It’s “processed” instantly and ready for viewing or printing using your own
inexpensive color printer. No more sifting through stacks of prints of marginal
images. You decide which images to print and whether to make them
4 x 6 inches or 5 x 7 inches or some other size. You can print them at home
inexpensively or take a tiny digital memory card to a nearby retailer and
have even more inexpensive prints made for you in minutes by an in-store
digital print lab.
On the other hand, if you want to have full control over your photos, digital
photography gives you that, too, to a degree that has never before been
possible. Perhaps your images aren’t exactly right or could benefit from a
little cropping or other improvements. You can fix bad color, remove your
ex-brother-in-law from a family photo, or adjust the borders of an image to
focus on the most interesting subject matter. All you need is an image editor,
such as Photoshop or Photoshop Elements.


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Nothing’s super about superfluous pixels

Nothing’s super about superfluous pixels
If you think you can never be too rich, too thin, or have too many megapixels,
think again. Megapixels have a dark side, too, Luke. Unnecessary pixels
lead to bigger image files, usefulewhen you actually need all those pixels, but
they’re a potential nuisance if you don’t. Few people have the problem of
being able to afford a camera that has a resolution significantly higher than
they really need, but if you’re in that elite class, consider these caveats:

1. Excess megapixels eat up your memory cards. All dSLRs store images on
solid-state memory cards. I own three cards for my 10MP camera, each of
which can store about 272 pictures in the best high-resolution shooting
mode. Most of the time, I have plenty of digital film for any day’s shooting,
and I can always drop to a lower resolution mode to stretch my memory
cards further. However, if I used the same vendor’s top-of-the-line 24.5MP
dSLR, each of those cards could hold only 85 images at the top quality setting.
I’d have to own a lot more memory cards to do the same work!

2. Extra resolution taxes your computer. Fat photo files take a long time to
transfer to your computer, and your image editor needs fast processing
speeds and a lot of memory to manipulate those files. That high-end digital
camera that you’re lusting after might call for a high-end computer, too.

3. More pixels need more storage. Very high-resolution files can be several
times larger than your run-of-the-mill high-resolution image files. If
you want to keep a lot of these files available on your hard drive, you
need a large disk — and probably a lot of extra CDs, DVDs, or external
hard drives to which you can archive them for permanent storage.

Article From : Digital SLR Cameras and Photography For Dummies 3rd Ed. (Book)

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Deciding how many pixels your camera needs

Deciding how many pixels your camera needs

People contemplating the purchase of a digital SLR often agonize over how

many megapixels they should buy, even though you may find other factors

(such as ease of operation and the kind and quality of lenses available for a

particular dSLR) considerably more important in the long run. To a certain

extent, vendors have (at least temporarily) alleviated this agony. In the past

year or two, a surprising number of vendors have settled on 12MP as a basic

benchmark number.

Nikon, for example, has three 12MP digital SLR cameras — a basic entry-level

model, an intermediate amateur camera, and a feature-packed advanced

model that both serious amateurs and professionals love. Canon, too, has

introduced several 12MP models, and other vendors have followed. Of

course, for most applications, you don’t really need more resolution. But,

with competitive pressures being what they are, I don’t know just how long

the 12MP plateau will remain the standard. (I urge those of you reading this

in 2012 with your $499 21MP cameras to refrain from laughing.)

Although more pixels usually equal more resolution and more detail in your

pictures, the number of pixels you actually need depends on several factors:

1. How you plan to use the photo: An image that you place on a Web site

or display in presentations doesn’t need to have the same resolution as

one that you use professionally — for example, as a product advertisement

or a magazine illustration.

2. How much manipulating and cropping you plan to do: If you want

to give your images quite a workout in Photoshop or you often crop

small sections out of images to create new perspectives, you want all

the spare pixels that you can muster because high-resolution images

can withstand more extensive editing without losing quality than lowresolution

images can.

3. How much you plan to enlarge the image: Many people view most of

their images on a computer display or in 4-x-6-inch to 5-x-7-inch prints.

Any dSLR has enough megapixels for those modest applications. If

you’re looking to make blowups bigger than 8 x 10 inches (for example,

to make posters or prints that you display on the wall), you need a

plethora of pixels.

4.The resolution of your printer: Most digital images are printed on

inkjet or dye sublimation devices that have their own resolution specifications,

usually from 300 dpi (dots per inch) to 1440 dpi and beyond.

Printers work best with images that more closely match their own

ability to print detail.

If you primarily want to create prints, the following section can help you

gauge which capabilities you need in your camera and printer so that you

can get the best output possible.

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Megapixels and Why dSLRs Have More of Them

Megapixels and Why dSLRs Have More of Them

If you’ve been working with digital images for a

while, you know that pixels are your pals. They’re

the basic building blocks that make up an image. The

term pixel is a portmanteau, which was Lewis Carroll’s

term for a new word created by combining two old

words, such as slimy and lithe to create slithy. In this case,

pixel stands for picture element and came into vogue when

computer imaging became popular.

However, you’ve seen pixel-like components outside the digital realm, in

pointillist paintings, such as the illustrations Georges Seurat created for the

Broadway musical Sunday in the Park with George. You also see pixel-like

components in newspaper halftone photos. All these images are made up of tiny dots that you can see vividly up close, but those dots blend to create

continuous tones and colors when you view them from a distance,The difference between these picture elements and those used to represent digital photos is that the digital pixels are all the same size

and shape, varying only in brightness and hue.

In digital images, the pixels — tiny squares that you can see individually only

under magnification — are arranged in rows and columns like a checkerboard

that happens to measure hundreds of squares on a side. Among current digital

SLRs, this array is a minimum of 3,008 pixels wide and 2,000 pixels tall,

for a total of 6 million pixels in all. (Although the last of these 6-megapixel

cameras will probably be phased out early in the life of this book.) The latest

digital SLR cameras for consumers actually offer many more pixels than that,

from 3,872 x 2,592 (10 million) pixels for certain entry-level models to 4,288

x 2,848 (12 million) pixels or more for the majority of digital SLRs. Of course,

pro and advanced amateur cameras go up to 6,048 x 4,032 (24.5 million)

pixels. That’s a lot of pixels! Those pixel counts represent the number of light-sensitive areas in the

digital camera’s sensor, and the total is usually expressed in terms of megapixels

(millions of pixels), and abbreviated MP. The precise dimensions

might vary, depending on the exact sensor used. For example, the Nikon D40

uses a 3,008-x-2,000-pixel sensor, but the original Canon Digital Rebel had a

3,072-x-2,048-pixel array. Both cameras were considered 6MP dSLRs, even

though the arrangement and number of pixels is slightly different.

Pixelementary, my dear Watson

Pixels, represented by individual

light-sensitive areas in a sensor

called photosites, capture the detail

in your image. In general terms,

the more megapixels, the better

because when you add pixels, the

ability of the sensor to capture detail

improves and the effective resolution

of the sensor rises.

It’s like dividing a foot-long ruler into

1,200 increments rather than 120.

In the former case, the ruler could

measure things with 1/100-of-an-inch

accuracy; in the latter, you could

use the rulings only in 1/10-of-an-inch

chunks. In the same vein, a sensor of

a particular size that has 12MP can

show much finer detail than one the

same size that has only 6MP. when

the size of the pixels decrease, more

of them can fit on a sensor to capture

ever smaller details of the original

image. However, image quality

involves more than resolution alone.

Many 10MP dSLRs produce sharper

and more noise-free results than

12MP non-dSLRs simply because the

10MP dSLR’s sensors are physically

larger and each individual pixel is

better than a non-dSLR’s sensor’s.

Some dSLRs even outperform other

dSLRs that have more resolution

because of the quality of the sensors,

lenses, or electronic circuitry in the outperforming dSLR. For example, I have a 12MP pro dSLR that consistently

produces better results than a 14MP entry-level model from another vendor,

particularly under lower light levels. The raw number of megapixels gives

you only a guideline, even though the more pixels, quite often the better your

images look.

Article From : Digital SLR Cameras and Photography For Dummies 3rd Ed. (Book)

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A closer look at shutter lag

A closer look at shutter lag
Typically, the snapshooter can finally coax a
niece or nephew into smiling and press the shutter
release to capture the moment. Or a batter
swings lustily at a fat pitch and lofts the gamewinning
run into the stands just when the photographer
presses the shutter button. However,
the crucial moment is never captured on pixels.
Instead, the digicam’s autofocus and autoexposure
mechanisms make some last-minute
adjustments, a bunch of electronic components
process some algorithms, and (eventually) the
camera takes the picture. This period of time is
measured in ohnoseconds; ohnoseconds are
the interval between when you want to take the
picture and when you actually hear the shutterclick
sound that your camera emits. I’ve tested
hundreds of digital cameras, and the actual
elapsed time for non-SLRs ranges from 0.6
seconds to 1.2 seconds under bright, contrasty
lighting conditions, or up to 1 to 2 seconds in
dimmer lighting. It just seems even longer than
that.

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A dSLR works like a camera

A dSLR works like a camera

Another reason why digital SLRs have improved performance is that they’re

easier to use, so you, as the photographer, can work quickly while you shoot.

The manufacturers configure most point-and-shoot cameras for consumers

who simply want to grab a quick snapshot, instead of investing some artistry

in creating a photograph.

Moreover, point-and-shoot cameras tend to be designed by an engineer who

did a really, really good job adding photo capabilities to the vendor’s cellphone

line last year, and who obviously must be the best choice to cobble

together a full-fledged digital camera. Indeed, the line between cell-phone

cameras and digital snapshot cameras is blurring all the time. (I predicted a

few years ago that soon photographers would be able to get only two kinds of

cameras: cell-phone-integrated point-and-shoot cameras and digital SLRs.)

Like a cell phone, non-SLR digital cameras tend to have most of the controls

tucked away out of sight in the menu system, where the average consumer

never has to see them and where the photo enthusiast has to hunt for them.

Digital SLRs, on the other hand, are always designed by a team of engineers

who have extensive photographic experience. They know which controls a

photographer absolutely needs and which controls they can bury away in the

menus because you access those controls only when setting up the camera

and maybe once a month (if that) thereafter.

Digital SLR designers know that you don’t want to go three levels deep into a

menu to set the ISO sensitivity or adjust white (color) balance for the type of

illumination that you’re using. You want to press an ISO or a WB (white balance)

key and dial in the setting without giving it much thought. You don’t

want to activate an onscreen display to set shutter speed or aperture — you

want to have separate dials for each. Nature intended that you zoom and

manually focus your camera by twisting a ring on the lens — not by pressing

a little lever and letting a motor adjust the lens at its own pace.

Simply having a camera that operates like a camera, rather than like a DVD

player, makes your picture-taking much easier and faster.

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Taking photos faster

Taking photos faster

Everything about a digital SLR seems to work more quickly and responsively.

You may find that speed important when you want to make a grab shot on

the spur of the moment or expect the camera to take an action photo right

now when you press the shutter release at the peak moment. Many pointand-

shoot digital cameras are downright sluggardly compared to dSLRs when

it comes to performance (although some vendors have worked very hard

to close the gap). You can find improved speed in three key areas, which I

explain in the following sections.

Wake-up time

You can have a relatively fast non-SLR digicam powered up and ready to snap

its first photo in as little as two seconds. Many of these cameras take three

to four seconds to emerge from their slumber. Worse, because they consume

so much power (thanks to the rear-panel LCD), these cameras may go into

stand-by mode or shut off completely if you don’t take a picture for 30 to

60 seconds.

When you flip the power switch of a dSLR, the camera is usually ready to

take the picture before you can move the viewfinder up to your eye. Some

dSLRs are ready to go in 0.2 of a second! Digital SLRs don’t need to go to

sleep, either, because they consume so little power when not in active use.

I’ve left dSLRs switched on for days at a time with little perceptible draining

of the battery (but not in Live View mode, of course). Certainly, the autofocus

and auto-exposure mechanisms go on standby a few seconds after you move

your finger from the shutter release, but you can have them available again

instantly by giving a quick tap to the button.

Shot-to-shot time

Conventional digital cameras have limits on how quickly you can take pictures

in succession. Unless you’re using the motor-drive-like burst mode, one

shot every second or two is about all you can expect. Even in burst mode,

you’re lucky to get much more than one to three frames per second for 5 to

11 shots, max. Some point-and-shoot cameras do allow you to fire off shots

continuously for longer periods (in some cases, until the memory card is

full!), but you don’t find such speediness in the average entry-level digital

snapshot camera.

But all digital SLRs have relatively large amounts of built-in memory that

temporarily store each photo that you snap before the camera transfers it to

your memory card at high speed. You can probably take pictures in singleshot

mode as quickly as you can press the shutter release, and for at least

eight to ten shots before a slight pause kicks in. If you use a fast dSLR that

has some quality level settings, you can often keep taking pictures for as long

as your finger (or memory card) holds out.

A dSLR’s burst mode can typically capture three to nine frames per second

for 12 to 30 shots, depending on the speed of the camera and the quality

level you choose — low quality (high compression) settings produce smaller

images that the camera can write to the memory card quickly .

No common point-and-shoot camera comes anywhere close to that level of

performance at full resolution, even though a few can shoot at sustained frame

rates that allow you to produce movie-like effects with your still images.

Shutter lag

When I’ve spoken before groups promoting my other books, such as Digital

Photography All-in-One For Dummies, 4th Edition (Wiley Publishing, Inc.),

here’s the number one question I get from new digital photographers —

“What can I do about shutter lag!?!” Digicam owners seem to really dislike

their camera’s shutter lag — the pause between the moment you click the

shutter button and the moment the sensor captures a slightly different

image. Some snapshot cameras are worse than others, of course, but you can

still find many models available that produce an annoying lag between pressing

the button and taking the picture.

Digital SLRs also experience shutter lag, but it’s likely so brief — on the order

of 0.1 to 0.2 of a second — that you never notice it. Of course, dSLRs have

little shutter lag only most of the time. Point your lens at a difficult-to-focus

subject, such as the sky, or try to take a photo under low light, and your

speedy autofocus lens might hunt back and forth while you gnash your

teeth in frustration. 

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Flexing the powerful sensor of the dSLR Camera

Flexing the powerful sensor of the  dSLR Camera
With very few exceptions, digital SLR sensors are much bigger than their
point-and-shoot camera counterparts, and this size gives them a larger area
that can capture light and, potentially, great sensitivity to lower light levels.
(Some non-SLR cameras give up compactness to provide somewhat larger
sensors, but they’re still fairly rare.)

A dSLR’s extra sensitivity pays off when you want to
1. Take pictures in dim light.
2. Freeze action by using shorter exposure times.
3. Use smaller lens openings to increase the amount of subject matter
that’s in sharp focus.

Within the Canon digital camera
line alone, you find digital SLRs that
have 22.2mm-x-14.8mm to 24mm-x-
36mm sensors (the size of a 35mm
film frame). By comparison, some
of Canon’s digital point-and-shoot
cameras use a sensor that measures
only 7.8mm x 5.32mm. Put in terms
that make sense to human beings,
the dSLR sensors have 8 to 20 times
more area than their Lilliputian
point-and-shoot sensor-mates.

If you think of a sensor as a rectangular
bucket and the light falling on
it as a soft drizzle of rain, the large
buckets (or sensors) can collect more drops (or the particles of light called photons) more quickly than the small ones. Because a certain minimum
number of photons is required to register a picture, a large sensor can collect
the required amount more quickly, making it more sensitive than a smaller
sensor under the same conditions.
In photography, the sensitivity to light is measured by using a yardstick
called ISO (International Organization for Standardization). Most point-andshoot
digital cameras have a sensitivity range of about ISO 50 to ISO 100 (at
the low end), up to a maximum of ISO 800 to ISO 3200 (at the high end). Some
point-and-shoot models have even higher sensitivity settings, but it remains
to be seen how useful these ultra-high ISO non-SLR models are. Indeed, many
models that have high ISO settings generally don’t do a very good job in
terms of image quality.
In contrast, digital SLRs — which have more sensitive sensors and larger
light-gathering pixels — commonly have usable ISO settings of up to at least
ISO 1600. Many are capable of ISO 3200 or may range up to a lofty ISO 25600!
This extra speed does have a downside, as you can see in the following section.
But, in general, the added sensitivity allows people to shoot photos in dim
light, take action pictures, or stretch the amount of depth-of-field available.
Reducing noise in your photos
Visual noise (or just noise) is that grainy look that digital photos sometimes
get, usually noticeable as multi-colored speckles most visible in the dark or
shadow areas of an image. Although you can sometimes use noise as a creative
effect, it generally destroys detail in your image and might limit how
much you can enlarge a photo before the graininess becomes obtrusive.
The most common types of noise are produced at higher sensitivity settings.
Cameras achieve the loftier ISO numbers by amplifying the original electronic
signal, and any background noise present in the signal is multiplied along with
the image information.
Point-and-shoot digicams often don’t have ISO settings beyond ISO 1600
because the noise becomes excessive at higher ratings, sometimes even
worse than you see . However, you can
boost the information that the big dSLR sensors capture to high ISO settings
with relatively low overall noise. I’ve used digital SLRs that had less noise at
ISO 1600 than some poor-performing point-and-shoots displayed at ISO 400.
Obviously, the large sensors in dSLRs score a slam-dunk in the noise department
and make high ISO ratings feasible when you really, really need them.

Noise doesn’t always result simply from using high ISO settings: Long exposures
can cause another kind of noise. Although some techniques can reduce
the amount of noise present in a photo (as you can discover in Chapter 2), by
and large, digital SLR cameras are far superior to their non-SLR counterparts
when it comes to smooth, noise-free images.
Thanks to the disparity in size alone, all sensors of a particular resolution
are not created equal, and sensors that have fewer megapixels might actually
be superior to high-resolution pixel-grabbers. For example, most older
10-megapixel dSLRs produce superior results to some of the newest
12-megapixel non-SLR digicams. So, no matter how many megapixels a
point-and-shoot camera’s sensor can hoard, that sensor generally isn’t as big
as a dSLR’s. And when it comes to reducing noise, the size of the sensor is
one of the most important factors.


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Improving Your Photography with a dSLR

The differences between digital SLRs and the camera that you used before you saw the (digital SLR) light depends on where you’re coming from. If your most recent camera was a point-and-shoot digital model, you know the advantages
of being able to review your photos on an LCD screen an instant after you
take them. And, if you’re serious about photography, you also understand the
benefits of fine-tuning your photos in an image editor. If you’re making a longdelayed
switch to a digital SLR from a film SLR, you’re likely a photo enthusiast
already and well aware that a single lens reflex offers you extra control over
framing, using focus creatively, and choosing lenses to produce the best perspective.
And, if you’re making the huge leap from a point-and-shoot non-SLR
film camera to a digital SLR, you’re in for some real revelations.
A digital SLR has (almost) all the good stuff available in a lesser digital
camera, with some significant advantages that enable you to take your photo
endeavors to a new, more glorious level of excellence. Certainly, you can
take close-ups or sports photos by using any good-quality film or digital
camera. Low-light photography, travel pictures, or portraits are all within the capabilities of any camera. But digital SLRs let you capture these kinds of
images more quickly, more flexibly, and with more creativity at your fingertips.
Best of all (at least, for Photoshop slaves), a digital SLR can solve problems
that previously required you to work long hours over a hot keyboard.
Despite the comparisons you can make to other cameras, a digital SLR isn’t
just a simple upgrade from a conventional film camera or another type of
digital camera. A dSLR is very different from a film SLR, even though some
vendors still offer film and dSLRs that look quite a bit alike and share similar
exposure metering, automatic focusing, and other electronics, as well as
interchangeable lenses. If you look closely, you can find that the digital SLR
camera is different than a film SLR, and you use it differently to take pictures.
In the sections that follow, I introduce you to the advanced features and
inner workings of a dSLR so that you can begin getting the most out of your
camera.

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dSLR: dNext Great Digital Camera

Surprise! Digital SLRs are now available in virtually every price range. As
recently as 2003 (the Dark Ages of digital photography), a basic entry-level
dSLR could cost $2,000 or more. At that time, the original Canon Digital Rebel
and Nikon D70 models made it possible for serious photographers to purchase
a real dSLR — with lens — for less than $1,000. A few years later, you
could get similar kits — but with more resolution and improved features —
for $599 or less. Today, you’d have difficulty finding a dSLR that doesn’t have
at least 12 million pixels of image-grabbing sharpness.

So, almost anyone can afford to make the jump to a digital SLR. If you already
have, you’ve discovered that the dSLR lets you take pictures the way they’re
meant to be taken. After they use other film or digital cameras, avid photographers
interested in taking professional-looking photos notice why dSLRs
stand out:

1. You can view a big, bright image that represents (almost) exactly what
you see in the final picture. No peering through a tiny window at a miniature
version of your subject with a tiny optical viewfinder. Digital SLRs
have big and bright viewfinders that show virtually the entire image, so
you don’t have to wonder whether you chopped off the top of someone’s
head. Using the optical viewfinder, which comes as standard equipment on
every dSLR, means that you don’t have to squint to compose your image at
arm’s length on an LCD (liquid crystal display) viewfinder that washes out
in bright sunlight. However, if lighting conditions permit, most digital SLRs
also allow you to preview your picture on the back-panel LCD (just like a
point-and-shoot camera), giving you the best of both viewing worlds.

2. A dSLR responds to an itchy trigger finger almost instantly. Forget
about pressing the shutter release and then waiting a second or two
before the camera decides to snap the shot. Although newer point-andshoot
cameras are more responsive than older versions, few match the
ability of dSLRs to crank out shots as fast as you can press the button.
Even fewer point-and-shoot cameras are capable of the four-to-nineframes-
per-second continuous shooting rates available with some of the
digital SLRs aimed at more advanced photographers.

3. You have the freedom to switch among lenses. For instance, you can
switch among an all-purpose zoom lens, a super-wide-angle lens, an
extra-long telephoto lens, a close-up lens, or other specialized optics
quicker than you can say 170-500mm F/5-6.3 APO Aspherical AutoFocus
Telephoto Zoomexpialidocious. (Best of all, you don’t even have to know
what that tongue-twister of a name means!)
Just be prepared to succumb to lens lust, a strange malady that strikes
all owners of dSLRs sooner or later. Before you know it, you find yourself
convinced that you must have optical goodiesfor taking photos of wildlife
from enough of a distance to
avoid scaring away the timid
creatures. If you’re ready to say sayonara to film, adiós to poorly exposed and poorly composed pictures, and auf Wiedersehen to cameras that have sluggardly performance, it’s time to get started.The sections that follow (as well as other chapters in this part) introduce you to the technical advantages of the digital SLR and how you can use the dSLR features to their fullest. When you’re ready to expand your photographic horizons even further,

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dSLR camera's lens

The digital single-lens reflex (dSLR) is the great step upward for photographers

who want to expand their creative horizons — or simply just get

better pictures. Whether you want to become a serious photo hobbyist, have

a hankering to turn pro, or want to take advantage of the improved control

that digital SLRs give you over your photography, discovering how to use

this tool of the future should be high on your priorities list.

The latest digital SLRs have features that no one had even dreamed of back

when I wrote the first edition of this book. All the major bugs of the earliest

dSLRs have been magically transformed into killer features in the latest

models. Today, you can preview your images by using Live View features

before you snap the shutter. Dust that collects on the sensor causes much

less of a problem thanks to built-in sensor-cleaning features. You get better

image quality than in earlier models, thanks to higher resolutions (you can

commonly get 15 megapixels and up, even in low-cost dSLRs), super-sensitive

sensors that can capture images in near darkness, and inexpensive but effective

anti-shake technology built into cameras or lenses.

Most recently, the only remaining drawback of digital SLRs — the fact that

you couldn’t shoot movies (long a common feature in point-and-shoot

cameras) — was swept aside with the introduction of new models that grab

HDTV-quality video with sound.

Best of all, all these capabilities are eminently affordable. Digital SLRs in the

$500-to-$1,000 range today can outshoot the $5,000 professional models of

five years ago and are light-years ahead of even the best point-and-shoot

models. The dSLR provides more control over what portions of your image

you want in sharp focus, boasts lower levels of the annoying grain effect

called noise, and operates fast enough to capture the most fleeting action.

If that isn’t enough, you can change lenses, too, adding super-wide perspectives

or the huge magnification possibilities of long, long telephoto lenses to

your repertoire.

Almost all the other advantages of digital photography come with your digital

SLR camera, too. You can review your image immediately, upload the

photo to your computer, make adjustments, and print a sparkling full-color

print within minutes. You never need to buy film. You decide which images

to print and how large to make them. You can proudly display your digital

photographic work framed on your wall or over your fireplace. You can even

make wallet-sized photos, send copies to friends in e-mail, or create an online

gallery that relatives and colleagues can view over the Web.

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