21 Sep 08 About Digital Cameras
Author: Mohit Sharma
The digital cameras have the ability to display the images on the screen immediately after the image is recorded. The images to be captured can be seen on its screen instead of its viewfinder. This way you can get a clearer preview of the image you are intending to capture.
The digital camera outdoes the traditional film camera in its image storing capacity too. The digital camera has the ability to store thousands of images on a single memory device. In addition you can even erase or unload the captured images onto your computer and reuse the camera’s inbuilt memory. In some cases you can even put a new memory card and store more pictures. Digital cameras also allow you to edit images. When capturing videos, digital cameras have the ability to record sound too, thus making video capturing a fun experience.
There are varied categories of digital cameras:
Video cameras: They are the cameras that exclusively record moving images.
The professional video cameras are the ones used for film production, etc. these have multiple image sensors thus enhancing the resolution of the end product. These do not have a inbuilt VCR or microphone.
The camcorder is another type of digital camera that has a microphone to record sound and an LCD screen to view the image that you are going to capture. This is mostly used by amateurs.
The web cameras are the type that is attached to the computers. Some of these web cameras have microphones, while some of them also include zoom abilities.
Compact digital cameras: They are small and portable; the smallest of them are called subcompacts. They are easy to use with not many special features or high picture quality. They have built in flash of not a very high power, but sufficient for close objects. It also permits live preview. They have a greater depth of field thus allowing objects from larger distances to come in sharp focus.
Bridge cameras: They are higher-end digital cameras that look a lot like Digital SLRs. Bridge cameras have the same advanced features as SLR and the live preview like the compact digital cameras.
Digital single lens reflex cameras: This is the digital camera that works like the single-lens reflex with a film.
Digital rangefinders: A rangefinder is an optical mechanism used to measure subject distance. They were once widely used on film cameras.
Professional modular digital camera systems: Mostly these cameras are used in studios for commercial production. Since they are bulky and difficult to carry they are rarely used in action or nature photography. They can be changed to digital or film cameras by simply replacing the back part of the entire device.
Line-scan camera systems: This type of camera is used in industrial areas in order to capture an image of a constant stream of moving material. This technology has the ability
These cameras are almost solely used in industrial settings to capture an image of a constant stream of moving material. Line-scan technology is capable of capturing data extremely fast, and at very high image resolutions.
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20 Sep 08 Digital Camera Basics-images
Author: Brian Lee
In the past twenty years, most of the major technological breakthroughs in consumer electronics have been built around the same basic process: converting conventional analog information (represented by a fluctuating wave) into digital information (binary information represented by ones and zeros, or bits). This fundamental shift in technology has changed how we handle visual and audio information — it completely redefined what is possible.
The digital camera is one of the most notable examples of this shift because it is so truly different from its predecessor. Conventional film cameras depend entirely on chemical and mechanical processes — you don’t need any electricity whatsoever to operate them, other than for a flash. On the other hand, all digital cameras have a built-in computer, and all of them record images electronically.
The new approach has been enormously successful. Since film usually provides better picture quality, digital cameras have not completely replaced conventional cameras. But, as digital imaging technology has improved, and prices dramatically decreased, digital cameras have rapidly become more popular.
In this article, we’ll find out exactly what’s going on inside these amazing digital-age devices.
Understanding the Basics
Let’s say you want to take a picture and e-mail it to a friend. To do this, you need the image to be represented in the language that computers recognize — bits and bytes, or binary information. Essentially, a digital image is just a long string of 1s and 0s that represent all the tiny colored dots — or pixels — that collectively make up the image. If you want to get a picture into this form, you have two options:
1) You can take a photograph using a conventional film camera, take the film to a developing lab that processes the film chemically, prints it onto photographic paper, and then place the picture on a digital scanner to sample the print (record the pattern of light as a series of pixel values).
2) You can directly sample the original light that bounces off your subject, immediately breaking that light pattern down into a series of pixel values — in other words, you can use a digital camera.
At its most basic level, this is all there is to a digital camera. Just like a conventional film camera, it has a series of lenses that focus light to create an image of a scene. But instead of focusing this light onto a piece of film, it focuses it onto a semiconductor device that records light electronically. A computer then breaks this electronic information down into digital data. All the fun and interesting features of digital cameras come as a direct result of this process.
Instead of film, a digital camera has a sensor that converts light into electrical charges.
The image sensor employed by most digital cameras is a charge coupled device (CCD). Some cameras use complementary metal oxide semiconductor (CMOS) technology instead. Both CCD and CMOS image sensors convert light into electrons. Without getting too technical, a simplified way to think about these sensors is to think of a 2-dimentional array of thousands or millions of tiny solar cells.
Once the sensor converts the light into electrons, it reads the value (accumulated charge) of each cell in the image. This is where the differences between the two main sensor types become a factor:
A CCD transports the charge across the chip and reads it at one corner of the array. An analog-to-digital converter (ADC) then turns each pixel’s value into a digital value by measuring the amount of charge at each photosite and converting that measurement to binary form. CCD sensors create high-quality, low-noise images. CCD sensors have been mass produced for a longer period of time, so they are more mature. They tend to have higher quality pixels, and more of them.
CMOS devices use several transistors at each pixel to amplify and move the charge using ordinary wires. The CMOS signal is digital, so it needs no ADC. Because each pixel on a CMOS sensor has several transistors located next to it, the light sensitivity of a CMOS chip is lower (many of the photons hit the transistors instead of the photodiode.) CMOS sensors traditionally consume little power. CCDs, on the other hand, use a process that consumes lots of power.
The amount of detail that the 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, or 20 million pixels for large-format cameras. For comparison, Hewlett Packard estimates 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.
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20 Sep 08 How to Find a Cheap Digital Camera
Author: Matt Peters
Advances in modern science ushered in a wave of new technology that the world can enjoy. In the old days, photographers used actual bulbs for camera flash. Only photographers carry cameras because lugging them around isn’t really fashionable at that time. Discoveries and development of cameras produced the digital camera, wherein taking pictures isn’t so cumbersome anymore. It is less expensive because you can see the images before printing them so you could choose what to actually print. The images could also be uploaded to your computer for storage and further manipulations. These days, it not unusual to carry a compact digital camera. It’s perfect for capturing those random wacky moments with your friends.
The only problem it seems is finding a cheap digital camera. Can you even find one? Because of the features that are offered by digital cameras, they are often costly. That is enough to make any person have second thoughts about buying one. But for someone who considers photography a passion, affordability is relative. You just have to set a budget before buying a camera. You can find a cheap digital camera that is just right for you if you look hard enough. Don’t buy one that is more than you can afford, even if it has a lot of features. Make sure that you can actually use these features so that you can get your money’s worth. Consider your lifestyle and your objectives. Do you plan to spend a lot of time taking pictures or do you just want something small that can fit in your bag? If you are still a beginner, don’t buy a high-end professional camera just for the assurance of image quality and zoom performance. Instead, buy a cheap digital camera that is compact but has powerful features and easy to carry around. Explore the basics before cashing out on expensive professional cameras.
Though these are very important points to ponder when buying a cheap digital camera, you also have to consider the performance and features of your camera. Check the megapixels, zoom capability, image quality, type of media and battery. These are actually features that digital cameras highlight in advertisements.
· Megapixels – They are not the be-all and end-all of digital cameras. Salespeople like to throw this information to you because it promises clearer images. But this is just one factor that comprises your digital camera. You have to check the megapixels’ quality. Most image sensors can only find certain hues like red, blue and green. They can’t detect all three at the same time.
· Zoom capability – You’ve seen advertisements like 10x digital zoom or 5x zoom capability. While it is true, advertisers often forget to highlight optical zoom, which is actually more important. The difference is that with digital zoom, your image gets broken into small pixels if you enlarge it on your computer. If your camera has high optical zoom, you would not see pixelated images if you enlarge the image.
· Image quality – Check the quality of your image after you take a picture. Is it fuzzy or pixelated? Sharpness of colors is very important.
· Type of media – This is the memory of your digital camera. Find a memory card or stick that is compatible with your other equipment so it is easier to upload your images.
· Type of battery – See to it that your cheap digital camera doesn’t require expensive batteries or that it allows rechargeable batteries.
These points would help you decide on what kind of cheap digital camera to buy. Like what was mentioned earlier, affordability is relative for the passionate photographer. Find your niche by choosing the best but cheap digital camera.
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20 Sep 08 Digital Camera: the Future of Cameras
Author: Nicholas Tan
Basically a digital camera is a deice use to capture pictures without the use of films. Unlike the conventional camera, the digital camera does not rely on mechanical and chemical processes. It has a built in computer and records the images it captures in an electronic form. Having and operating one does not even require the use of electricity.
Since the images that a digital camera captures is in electronic form, it is a language recognized by computers. This language is called pixels, tiny colored dots represented by ones and zeros that make up the picture that you just took. Just like any conventional cameras, a digital camera is furnished with a series of lenses that focus the light and creates the image that you want to capture. The difference here is then; a conventional camera focuses its light on a film while a digital camera focuses the light into a semiconductor device that electronically records the light. Remember the built in computer, it comes in here and breaks this information to digital data resulting to all the features of the digital camera.
Another feature of the digital camera is that it has a sensor that converts light into electrical charges. A charge coupled device or CCD is an image sensor that is found in a digital camera. While other low-end digital camera use complementary metal oxide semiconductor or CMOS as an image device, it can still become better and more famous in the future but most engineers are do not believe that it can replace the CCD for higher-end digital cameras.
A collection of tiny diodes, the CCD gathers electrons when they are struck by photons or the light particles. Each diode or photosite is sensitive to light, meaning that the brighter the light, the number of the electrons gathering will be larger
The price of a digital camera nowadays have been depreciating, one of the main reasons of this is because of the introduction of CMOS image sensors, this is because CMOS sensors are less expensive and are easier to manufacture than CCD sensors. A CCD and CMOS sensor works the same way at first, by converting the light electrical charges into photosites. Simply putting it, is to think that a digital camera works in such a way as thinking that the millions of tiny solar cells, each of which forms a part of the whole image. Both CCD and CMOS do this task using different methods.
When shopping for the best digital camera, take note of these key features.
Image quality. Check the resolution of the camera. The higher the resolution, the more thou will be able to enlarge your picture without the grainy or the out-of-focus effect that we all want to avoid.
Lens. Choose a digital camera with better digital zoom. The digital zoom of the camera will enable you take the pixels from the image sensor and incorporate them to make an image.
Power. Always opt for rechargeable batteries, they can always come in handy, plus you don’t waste as much money on the disposable ones.
Options. So you can brag to your friends how good a photographer or artist you are. Or choose the one that gives options that best cater to your lifestyle, so you won’t ever whine how you never get the right pictures.
Memory. If you’re a photo freak, be sure that you have enough memory in your camera to take all the wacky, freaky, funny and just about any photo you can. Think 512MB if you’re a photo junkie and takes pictures of just about anything.
Computer Interface. Always make sure that it is compatible with your PC, laptop, palmtop or whatever your local picture printer software is, you don’t want to go running around the whole state or the country looking for a computer that’s compatible with your digital camera, wont you?!
Physical. If you are going to be bringing it everywhere, choose a handy and portable digital camera. This way, it won’t always feel as heavy and bulky as those cameras that you see professional photographers are always dragging on their neck. Don’t they ever get tired of that?!
These are just the basic things you have to look for in a digital camera when you buy one. A digital camera is so great that it is quickly replacing all conventional cameras in the market, with all its technology and portability, truly the digital camera is the future of cameras.
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19 Sep 08 Slr Digital Camera: Advantages and Disadvantages
Author: Russ Snapper
A tough decision war happens to all who want to buy a digital camera, whether to buy a compact digital camera or an SLR digital camera. SLR is Digital Single-lens reflex camera, which is a standard tool for professional photographers. It provides the advantage of large, bright and accurate optical finder with large controls and fast operations.
Among the digital cameras, the SLR camera is the best for you provided if you are a family oriented person having a serious appetite for photography. For capturing pictures during family vacations, birthdays and holidays, the SLR camera will be the best companion. Though the point shoot cameras have increased to higher mega pixels, the choice of serious photography hobbyists and photographers is SLR. The clear reason for the choice is that SLR has the capacity for producing artistic photographs.
The main advantage and biggest difference that exit in the SLR is that there are more manual operations than the point-and-shoot cameras have. To get a perfect shot, your camera should be always in ready mode. SLR cameras offer instant start up and also minimum shutter lag. The point-and -shoot cameras have shutter lag of 2 or 3 seconds, which means you can miss a shot. The SLR camera’s shutter lag is less than a second and so you can get all the shots without miss. Another advantage is that the SLR cameras can accept interchangeable lenses. This helps you in getting best shots of sports and nature where you cannot go close for taking pictures. You can zoom the lens of SLR digital cameras and take close-ups. The other advantages are long battery life, high-speed continuous shooting, great image sensor and the ability to save RAW images.
The disadvantage is its larger size and you cannot fit it in your bag or purse. Not only larger in size, but also heavier and not suitable for vacations. It’s also very expensive when compared with compact and subcompact digital cameras. The SLR prices can range between $1,000 and $10,000. The best portrayal of SLR is its speed, clarity and optical system. It can be easily mistaken for a point-shoot camera but it is entirely different in the way it is used and the delivered picture quality. In real meaning, this camera enables you to look at the picture precisely without any alteration of digital features within the camera.
The digital SLR is built in such a manner that it enables to deliver high quality images. In a compact digital camera, the image that you see in the eyepiece or through LCD screen is generated digitally; but in SLR the image is sent by the lens and mirrors to viewfinder that reflects the images from one mirror to another. The digital SLR is versatile and that is why the image seen in an SLR is exact without any alteration. The interchangeable lenses allow you to utilize custom lens for a meticulous shot like Portrait, Landscape and Macro or Micro shots. Some lenses are even available for taking motion shots.
The image sensors in SLR provide good picture quality and quick shoot and click capability with no time lag. Detachable lenses give more attraction for photographers in choosing SLR as their choice. If you are not comfortable with manual operations SLR cameras have automatic settings and this provides transitional steps in learning to use an SLR.
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