As a popular hobby over the past 170 years, one feature that remained constant in photography is the need for a camera to be loaded with a film that needs chemical processing. In a traditional camera, the photographic film, a strip of plastic covered in chemicals that react when exposed to lights, is the crucial factor. In a digital camera, the place of the film is taken by a small chip called a CCD. CCD reacts to the light just as film does. CCD converts the light into a digital electronic form, instead of storing the image chemically which can be stored in a computer.
Computer programs can be used to sort digital images into an album on a personal computer (PC). Certain printers can directly be linked to the digital camera for making prints. Once this versatile piece of equipment is attached to a PC, one can open a world of photographic and artistic possibilities.
From the outside, cameras generally resemble normal film-based ones. There is a lens, a viewfinder, a shutter release button and a flash. However, what is different is the back of the camera which has a small, flat CCD panel which converts the received light into digital electronic data. The second difference is that digital cameras also have a LCD display panel on the back which can be used to preview pictures before they are clicked and to review stored images.
Digital cameras are fun and generally easy to use. If you are already familiar with computers, then there really is not much to hold you back from mastering the basics very quickly. At every level digital imaging offers a lot to the photographer. Today we take pictures and also take a look at the LCD display panel of a camera to make sure we get the shot we want. Various kinds of software then allow the user to change, print and even email these images. Some digital cameras also allow the use to take short movies that can be viewed on a TV screen.
So, let’s talk about the basics of this Digital Photography.
As mentioned above, the heart of any digital camera is a chip called CCD which converts light into digital electronic signals. A CCD has the more details it can record. Higher resolution adds to the cost of the digital camera but also increases the amount of data the camera can store. The choice depends on the purpose one intends to use it for. Using the images for putting on a Web page in a PC or sending holiday snaps does not require much higher than a 640 X 1200 or higher resolution.
A zoom allows us to focus onto a smaller part of an image, giving the effect of moving closer to the subject. Almost all digital cameras have either an optical zoom or a digital zoom, and some have both. The power of a zoom is measured by the number of times it can enlarge a section of the image – 6 X 12 zoom has the effect of doubling the size of an object. An optical zoom works by physically adjusting the distance between the lenses within the camera. This means one can zoom in as little or as much as one needs within the limits of the lenses.
An optical zoom enlarges an image by magnifying a part of the subject and the same effect can be obtained digitally by creating the digital image from a smaller area of the CCD. Digital zooms generally have a much higher power rating than their optical counterparts, but the quality of the image becomes poorer as one move to higher powers. This is so because, while an optical zoom focuses a part of the subject on the whole of the CCD and records more information about that part of the subject, a digital zoom only enlarges a small part of the CCD image without recording more information.
A lower resolution image will look terrible when printed as a large-size poster, but using the highest resolution for a picture destined for the internet is nothing short of overkill.
When you take a picture with a digital camera, it is stored in what is known as “memory”. This is an arrangement of silicon chips that can record information in exactly the same way as computers.
There are several types of digital camera memory, but for the purposes of generalization they can be divided into four basic categories- fixed format, card format, disk format and tape format. The kind that you select or that comes with your camera will depend on the model.
Fixed format memory is sometimes also referred to as “on-board memory” – basically, it means that the Images are stored on the camera hardware.
Card format memory is what you will find on the vast majority of medium to high-price cameras these days. Cards can be removed and replaced in seconds.
Disk format refers to mini CDs which are used by some camera manufacturers.
When you have taken your pictures on your digital camera, sooner or later you are going to want to make use of them. However, before you can do this you need to get them out of the camera. The usual method of saving your digital images is by connecting your camera to a computer and then transferring them across. This process is known as downloading. Once you have completed the procedure, you will find that you have quite a choice as to what you do with your pictures!
If the camera uses a floppy disk, the disk can be inserted into the floppy drive of the computer, the purpose being to link together digital information from the camera to the computer. But most digital cameras use a cable connecting the camera to the computer and this is known as a “serial link”. It is safer to turn off the computer first before connecting, as a wrong insertion can damage the electronic components. The manual of the computer should be read carefully.
The number of different memory cards on the market can seem quite bewildering to a novice photographer.
CompactFlash is the most popular card; these devices are, as the name would suggest, very small.
Flash cards are memory devices made using solid state computer chips. They have many plus points: they use very little power; they don’t require batteries to store your images; and they are very small.
Microdrives are quite distinct from other memory devices in that instead of using computer chips, they have a rotating disc inside. This has the benefit of allowing very high storage capacities.
SD cards are very similar to CompactFlash cards, but they are physically smaller. There is another version of the SD card available called the Multimedia card. These are lighter, and are often used in budget cameras and camera phones, which require particularly compact technology.
These wonderful devices are sometimes also known as “data pens”. They are basically tiny units, only about the size of a key fob. They contain solid State memory, and have a USB plug on one end so that they can be plugged directly into a computer without needing to turn it off and back on again. They are a very convenient way of carrying large amounts of data around.
Hard disk drives are available these days with enormous storage capacities – over 200GB units are available. However, if they are your preferred storage method, you will need to ensure that you are not wasting disk space by using inefficient storage formats. Also, make sure that you have a back-up copy of your pictures somewhere; this is because computer hard drives can and do fail, and there is nothing worse than losing all your images as a result.
If you prefer not to cram your computer’s hard drive with digital images – or you are worried that it might fail – the most popular alternative storage medium to choose is the compact disc. A compact disc (CD for short) can store 700MB; which is enough for about 50 medium resolution images. CDs have the advantage of being cheap, reliable, easy to use and even easier to store.
The DVD (digital video disc) is a derivative of the standard CD with a much larger storage capacity. These discs can accommodate digital video as well as still images.
There are two basic methods of getting your digital images from your camera onto a computer. If your model has a memory card, you have the option of removing it from the camera and plugging it into a card reader – which is itself plugged into your computer. You can also use a download cable to connect the camera directly to the computer.
Before you download your images, you will need to ensure that your computer has the necessary software.
To install the camera’s software, all you have to do is put the CD in the computer and the driver installation program will automatically start up. Then simply follow the instructions on the screen.
Once your computer has the necessary software installed, you need to find the right port for the download cable, whether USB or FireWire – usually at the back of the computer.
One of the things to watch out for when saving pictures onto your computer is that unless you are very careful, it can be extremely easy to over-write existing files. This is because some cameras give you little or no control over the filenames of your pictures. For this reason, it is a good Idea always to create a new folder when you are saving images. Another good idea is to add the date to the name you assign to the easy to forget naming conventions.
Once you have successfully saved your Images to your computer’s hard drive, you will need a method of viewing them. It is possible to use the computers file manager to display a Hit of the files; you can then view each file by double-clicking on it but this is a particularly ponderous process. It is much easier to use a special program to display your images as a series of thumbnails. These software packages enable you to click on individual thumbnails and then enlarge them or manipulate them as you see fit.
Some of the better cameras available – that is the mid-range models upwards – have the ability to load pictures from your computer onto your camera; this is known as “uploading”.
Uploading can be a very useful feature. For example if you are working away from home and have access to a computer, you can download all your images onto the hard drive and view them at large sizes on a monitor. You could then spend several days shooting even more pictures of everything in sight, and by downloading them whenever your cards fill up, you could then reformat the cards each time, This is quicker than erasing the images; and is a good method of cleaning up old and overfull memory cards.
Following this procedure means you will never have to worry about running out of card space. It is inevitable, though, that many of your shots will not be good enough to keep. However, when you review them, you can be very selective about which ones you take home, and have the added advantage of being able to upload them to your camera. This method of carrying pictures is also ideal if you want to show a series of images to a group of friends: Just connect your camera into a television set with a TV lead, and off you go!
All the digital images that you take are made up of minute individual components named pixels. In order to appreciate fully how your images work, you first need to understand pixels.
Since digital cameras take photographs that are composed entirely of individual pixels, it is worth taking the time to understand their significance. If you are going to take a series of images, it is sensible to set the camera’s resolution to suit the purpose of the pictures, and this is where pixels come in. If you are only going to use the images for low resolution situations, such as website advertisements where the file size is likely to be less than 100KB, then there is no point in using a setting that will result in a 15MB file. If you are new to kilobytes (KB) and megabytes (MB), let me explain that there are one thousand kilobytes to every megabyte. That means that for every picture taken at a 15MB resolution, you could have 150 pictures at a 100KB resolution.
When a camera processes a picture before storing it, the image is compressed. A good example of image compression is when a photograph is taken of something that has a lot of the same colour in it – for example the walls of a room. The compression would then be able to reduce the information required to represent the image because it would not have to store a different colour for every part of the picture. However, too much compression results in image degradation.
If you examine a list of computer files, you will see that they are each composed of a name followed by a full stop and three letters. These three letters are known as the “file extension”, and they describe to the computer what sort of file it is dealing with. Digital images can be stored in several different ways – these are known as “formats”. Each type is given a different name and the file extension is usually an abbreviation of this.
JPEG or JPG is the commonest format for image storage, and is usually the default output type of most cameras. If you want to send an image by e-mail, JPEG format is the one to use.
The bitmap or bmp image format was originally developed for monochromatic images in the days before colour monitors and printers became widely available. Microsoft still uses this format widely.
Tag Image File Format or TIFF makes it possible to produce the very high quality images needed for publication purposes. Unfortunately, files saved in TIFF format tend to be large so they can be inconvenient to handle.
The Graphic Interchange Format or GIF can produce fairly high quality images for small file sizes. This has made GIFs popular with website designers.
RAW format images are created when a camera stores a photograph with no compression or processing being performed. This means that the image has to be handled by a suitable program if you want to view it on a computer.