Digital Camera Basics - Want To Stop Being An Idiot And Learn How Digital Cameras Work?

With the advancement of the digital camera and the software that is made for them, most pictures look professional from the first click of the camera. But like most things, it is important to understand the "how and why" for higher quality results.

The basics of a digital camera revolve around terms like pixel, pixel count, white balance, sensor, sensitivity, optical zoom, or digital zoom. These improve your understanding of what digital photography is all about, and will help you become a more efficient photographer.

For example, one important term is digital sensor. A typical digital camera may have a digital sensor element that is as big as a small finger nail. Most 5MP digital cameras use a sensor that is 7mm x 5mm in size. This is much smaller than the size of the negative of a 35 mm camera. However, high-end digital cameras have large sensors, and generate superior images. These are important things to know, to see how pictures can be better or worse.

Digital cameras also have sensitivity settings similar to ISO ratings on film. Most digital cameras will have settings for sensitivity equivalent to ISO 100 and ISO 200. Many also have a setting for ISO 400. A few expensive digital SLR cameras with large sensors have settings for ISO 3200 or even for ISO 6400.

Most digital cameras have an optical and a digital zoom. An optical zoom lens works by changing the focal length and magnification while the zoom is being utilized - with the image quality remaining high. Digital zoom works by cropping the image to a smaller size. The cropped image is enlarged to fill the frame, causing a significant loss of quality.

The manufacturers of digital cameras use the term "pixel count" to describe their camera's image properties. The word pixel originates from "(PIC)ture (EL)ement"- with the use of phonics added for emphasis. It represents a single point in a graphic image - not a dot but an abstract sample that can be reproduced in any size, without a dot or square appearance.

A pixel is important to understand because it is the basic unit of measurement, used to define a digital photograph. The more the number of pixels per square inch, the higher the resolution of a digital picture, increasing its clarity. Some examples would be 2,400 pixels per inch, 640 pixels per line, or spaced 10 pixels apart. Designers, artists, and photographers sometimes interchange the pixel terminology, such as dots per inch (dpi) with pixels per inch (ppi). The dpi is used when it refers to the printer's resolution for the printing density. Each pixel is made up of three color channels - red, green and blue -- and has a numerical value of between 0 and 255.

The pixel count also decides the size of a print in case you want to print photographs. A 3MP camera can provide excellent 4x6 inch prints, while a 4 or 5MP digital camera can deliver high quality 8x10 inch prints. With a digital camera you can pick the white balance to suit the light source. This is meant to ensure that white looks white, and not yellow or blue. Normally, your digital camera will do this automatically. You can also set the white balance yourself for better effects.

Since each pixel generates three bytes of data, a photographer using a 3MP camera will need a storage space of 9 million bytes or 9MB to store a single image. This is a huge amount of space. Camera companies therefore allow for a compression of image using a format called JPEG. This reduces the file size significantly but while doing so a lot of data is lost. To overcome this problem companies have come up with different storage formats. Canon calls it RAW while Nikon calls it NEF. The data loss is less in these formats.

The low end cameras used by beginners can shoot images whose pixel count is one million is categorized as 1 MP or one million pixel camera because the intensity of each pixel is variable, with each pixel having three or four dimensions of variability - such as red, green and blue, cyan, magenta, yellow, and black. The high-end cameras used by professionals, can range from 14MP to 22MP with a pixel count as high as 14 million or 22 million per image.

The thing to remember is the higher the resolution, the more realistic the image is, matching closest what the actual image is. So take your time, do some research, and talk to people who know cameras. Otherwise, a lot of money will be spent on something that is barely adequate for what you want.

Check out http://www.digicamland.org/ for more articles on buying a digital camera and memory cards digital camera.

By Mike Singh

Digital Camera Basics

By Ernie Delgado

An electronics on-line discussion forum contains a story about an elderly woman who wanted a simple camera to take pictures of her grandchildren. When she received a digital camera for Christmas, she looked puzzled for a moment and then asked, "Where do you put in the film?" This humorous example demonstrates how the revolutionary technology of digital cameras may be mystifying for those who have difficulty grasping the concept of a "filmless" camera! For almost a century, photography enthusiasts sagely discussed such topics as 35mm film, light meters and F-stops; today, digital cameras have made such topics all but obsolete.

Howstuffworks.com contains an article by Gurevich, Karim, and Wilson that greatly simplifies an explanation of how digital cameras work. Very simply, they explain that CDs, mp3's, and DVDs all share the same technology: they convert traditional analog "wave" data into digital data based upon "bits." In so doing, this radical shift in technology has changed greatly - and forever - how we do things and what has become possible including digital "filmless" cameras. While film cameras depend upon chemical and mechanical processes, digital cameras contain a computer that records images electronically.

In 1994, Kodak and Apple developed and sold the first digital cameras. Today there are hundreds of models to choose from, depending upon the type of pictures you need, the complexity with which you're comfortable, and what digital camera you can afford. For everyday use, most people prefer a "point and shoot" camera that isn't complex, takes good quality pictures that can be loaded onto computers or printed for personal use and to send to friends, and is affordable. According to a number of consumer guides and customer reviews, the top ten digital cameras in the low, mid, and high price ranges are:

1. Nikon D300 (high)
2. Canon EOS 5D (high)
3. Canon EOS 40D (high)
4. HP Photosmart M547 (low, great value)
5. FujiFilm Finepix S700 (mid)
6. GE A730 (mid)
7. Nikon D200 (high)
8. Canon EOS Digital Rebel Xsi (high)
9. Panasonic Lumix DMC-FZ18 (mid)
10. Canon EOS 30D (high)

The point should be made that what constitutes a "great" digital camera is usually in the eye of the beholder. One person's "top ten" list is almost certain to differ from another person's. For example, a digital camera that is making devoted converts is the Casio Exilim series that sells in the mid-level price range, depending upon your digital camera photography needs. On the other end, Digital Camera.com rates the Pentax Optio E-10 as "the worst digital camera ever."

With all these differing opinions, what's the best way to buy the digital camera that's right for you? If you simply want to take personal pictures, choose a digital camera that has at least three megapixels. This will give you good quality pictures at a very affordable price. Remember that the higher the number of megapixels, the better quality your pictures will be, but the digital camera you choose will be more complex and more expensive. Also consider the size and shape of the camera; is it easy for you to carry in your purse or pocket? Finally, be sure your digital camera has at least 256-512 megabites of space on its memory card so you won't have to buy additional memory cards. Taking all these factors into consideration will help you enjoy capturing treasured memories for years to come.

Digital Camera Basics-Resolution - Exposure - Focus - and Storage

By B Lee

Resolution

The amount of detail that a camera can capture is called the resolution, and it is measured in pixels. The more pixels a camera has, the more detail it can capture and the larger pictures can be without becoming blurry or "grainy." High-end consumer cameras can capture over 12 million pixels. Some professional cameras support over 16 million pixels (megapixels), or 20 million pixels for large-format cameras. For comparison, it has been estimated that the quality of 35mm film is about 20 million pixels.

Exposure and Focus

Just as with film, a digital camera has to control the amount of light that reaches the sensor. The two components it uses to do this, the aperture and shutter speed, are also present on conventional cameras.

Aperture: The size of the opening in the camera. The aperture is automatic in most digital cameras, but some allow manual adjustment to give professionals and hobbyists more control over the final image.

Shutter speed: The amount of time that light can pass through the aperture. Unlike film, the light sensor in a digital camera can be reset electronically, so digital cameras have a digital shutter rather than a mechanical shutter.
These two aspects work together to capture the amount of light needed to make a good image. In photographic terms, they set the exposure of the sensor.

In addition to controlling the amount of light, the camera has to adjust the lenses to control how the light is focused on the sensor. In general, the lenses on digital cameras are very similar to conventional camera lenses -- some digital cameras can even use conventional lenses. Most use automatic focusing techniques.

The focal length, however, is one important difference between the lens of a digital camera and the lens of a 35mm camera. The focal length is the distance between the lens and the surface of the sensor. Sensors from different manufacturers vary widely in size, but in general they're smaller than a piece of 35mm film. In order to project the image onto a smaller sensor, the focal length is shortened by the same proportion.

Focal length also determines the magnification, or zoom, when you look through the camera. In 35mm cameras, a 50mm lens gives a natural view of the subject. Increasing the focal length increases the magnification, and objects appear to get closer. The reverse happens when decreasing the focal length. A zoom lens is any lens that has an adjustable focal length, and digital cameras can have optical or digital zoom -- some have both. Some cameras also have macro focusing capability, meaning that the camera can take pictures from very close to the subject.

Digital cameras have one of four types of lenses:

1) Fixed-focus, fixed-zoom lenses - These are the kinds of lenses on disposable and inexpensive film cameras -- inexpensive and great for snapshots, but fairly limited.

2) Optical-zoom lenses with automatic focus - Similar to the lens on a video camcorder, these have "wide" and "telephoto" options and automatic focus. The camera may or may not support manual focus. These actually change the focal length of the lens rather than just magnifying the information that hits the sensor.

3) Digital-zoom lenses - With digital zoom, the camera takes pixels from the center of the image sensor and interpolates (alters) them to make a full-sized image. Depending on the resolution of the image and the sensor, this approach may create a grainy or fuzzy image. You can manually do the same thing with image processing software -- simply snap a picture, cut out the center and magnify it.

4) Replaceable lens systems - These are similar to the replaceable lenses on a 35mm camera. Some digital cameras can use 35mm camera lenses.

Storage of Images

Most digital cameras have an LCD screen so you can view your picture right away. This is one of the great advantages of a digital camera -- you get immediate feedback on what you capture. Of course, viewing the image on your camera would lose its charm if that's all you could do. You want to be able to load the picture into your computer or send it directly to a printer. There are several ways to do this.

Although most of today's cameras are capable of connecting through serial, parallel, SCSI, USB, or FireWire connections, they usually also use some sort of removable storage device. Digital cameras use a number of storage systems. These are like reusable, digital film, and they use a caddy or card reader to transfer the data to a computer. Many involve fixed or removable flash memory. Digital camera manufacturers often develop their own proprietary flash memory devices, including SmartMedia cards, CompactFlash cards and Memory Sticks. Other removable storage device include floppy disks, hard disks (external, or microdrives), and writeable CD's and DVD's.

Regardless of what type of storage they use, all digital cameras need lots of room for pictures. They usually store images in one of two formats -- TIFF, which is uncompressed, and JPEG, which is compressed. Most cameras use the JPEG file format for storing pictures, and they sometimes offer quality settings (such as medium or high).

To make the most of their storage space, almost all digital cameras use some sort of additional data compression to make the files smaller. One compression routine takes advantage of patterns that repeat. The image can be reconstructed exactly as it was recorded, reducing the file size no more than 50%, often much less. Another compression routine called irrelevancy eliminates some of the more meaningless data, taking advantage of the fact that digital cameras record more information than the human eye can easily detect.

Brian Lee is co-owner of http://www.WorldCameraVideo.com, offering a large selection of digital cameras, camcorders, webcams, security cameras, and more.