How does the digital camera work?

How does the digital camera work?. 

Strictly speaking the digital photo cannot be compared with a film photo (at which you will use slides or negatives). From the technological point of view camera work is closer to a video filming, during which you receive the image at each moment.

Let’s look, how does the film camera work at first.

Simply speaking, the film camera consists of a lens system, a diaphragm and a shutter. The light having focused in a lens comes through the diaphragm while the shutter is open, falls on a photosensitive material. After photochemical processes exposure, the image is recorded on a film and can be developed on a printing paper.
Though the digital cameras are much alike film ones they use other principles of operation. Both cameras have lens system, diaphragm and shutter, but the methods of a record differ considerably.

The digital camera saves the image in the digital format on special medium. More precise consideration helps to understand the difference in methods of operation.

The heart of the digital camera the CCD (device with charging connection) matrix is hidden behind of the diaphragm and consists of photosensitive semiconducting elements made of set of silicon diodes. When light reaches a CCD matrix, it charges each of elements- pixels individually. Then this charge corresponds an electric pulse, and thus we receive digital data about illuminating intensity of each of pixels. As it is impossible to record information of the image completely, it is exposed to software processing for the lost data recovery and is recorded on a magnetic medium. Thus, the digital photo is a combination of a CCD matrix, software and memory cards activity which substitutes a film in the analogue camera.




The CCD matrix is no bigger than a nail and contains some millions photosensitive diodes (for example, in model --2500 there are 1,700*1,300 diodes) arranged on a matrix surface in a way of columns and pillars. As the matrix reacts only to brightness, the digital camera can display black-and-white picture only. However there is a way to catch all colors of a snapshot if you use different color filters in a lens: red, green, blue or another combination of colors blue, lilac, yellow, which with usage of the additional green filter gives the most realistic picture. The illuminating intensity rate is divided into 256 levels thus in total you have 256X256 X 256 = of 16, 7 million combination which replicate a full range of frame colours.

Due to this the color can be described by numeric value, and the information about it can be saved.

Capabilities of the image archiving.

Having a ready CD drive recorder you can create your own archive so-called digital photo album on a compact disc, which can be viewed on the TV through modern DVD players, or computer.
Your choice is a digital camera.


The digital camera has a number of advantages, in comparison with a film camera. The digital camera has a small screen, in which one can see what he receives on a snapshot. Therefore digital cameras allow to lay out frames, i.e. to dispose the objects of filming how they should look on a snapshot.

Screen of the LCD-display is much better for the inexperienced photographer, than an"«eye" of the mirror camera is. You can see what is shooted, the frame borders, sharpness and blurring of objects, the colours distribution and the illuminating intensity.

You are able to check at once after shooting, that what you have received on a snapshot. As a rule, in any digital camera, the result is imaged on some seconds after "click”

This option is possible to disconnect. Still it is possible to view frames on the display of a photographic camera and to be convinced, that you have managed to do all pictures.

There is also a capability of connection of the camera with the TV in many digital cameras, for review of snapshots on a large screen. Bad snapshots can be removed, and you may make other excellent frames in order to not print out all of them.

The absence of a film is one more large plus. To shoot 1000 frames using the film camera you will have to spend approximately 100 dollars. To shoot 1000 frames by the digital camera does not mean anything. After couple of months of digital filming you will begin «to "click" much more, you will take for a rule to duplicate frame, retake and to change an aspect angle. You will be able to use 10, 20, 50 frames on any « little flower», for obtaining the necessary colour, size, focus, aspect angle etc.

Close-up shooting, that's another matter. This kind of a photo is not accessible for a film camera, and even for more advanced devises which are not equipped with special lenses or nozzles. As a rule, everything, that is closer than a meter, at its best 50 centimetres from a lens, falls in a blurred zone. For digital cameras the considered standard is available close-up mode, permitting to shoot from 10-20 cm, and even from 1-5 cm. You have a capability to photograph hexapods, flowers and many other small-sized objects. Any, even not very beautiful at the first glance object easily will turn into a part of close-up composition.

Don’t forget, that the snapshot made by the digital camera can be edited on the computer. You can turn, cut off, modify colour, eliminate « a red eye » effect, use filters and etc.


What are the readout methods of memory cards?

The convenience of work with the digital image is determined by swapping speed of the image from the camera to the computer. Originally, the camera was hooked up to the computer directly through production port RS 232, thus the data swapping of the about 1 MB took 15 min. Today there are numbers of other data readout methods from Smart Card directly.

PCMCIA - adapter (MA-2E) allows reading out the data from a card by the portative computer
fast and easy.
USB - adapter (MAUSB-2E), which is hooked up directly to USB - port allows transmission of the data to the computer directly and very fast (average speed transfer is 12 bbit/sec., i.e. 32MB file can be transferred for 60 seconds). As the adapter it is capable not only to read out, but also to record the information, it can be used as a comfortable device substitute for the magnetic - optical disk reading, usual or ZIP- diskette, though to a smaller volume.

The adapter under 3.5 ” - diskette (MAFP-2E), which is pasted to the smart card, and the adapter is pasted into the computer instead of a diskette. It is an easy way enough for reading of the information.

Some printers can read out the information directly from a card that is one of the data transmissions from the printer on the computer modes.


What formats are used for the work with image?

There is a plenty of ways (formats), in which you can record the digital image. The most popular while working with a digital photo are two formats. The first one was originally designed for a Macintosh platform and then it was permanently updated and improved - TIFF (Tagged Image File Format), it was widespread among PC users. The TIFF format has set of advantages and is easy for usage; it supports a 32-bit digit capacity for the CMYK format that can be useful. For example, at a direct data printing from a screen of the monitor on the printer.
The second format - JPEG (Joint Photographers Expert Group) becomes more and more popular because of convenience of its usage in a network. This format has two features - full range of tints and low memory volume which is necessary for image storage (however is leads to a small loss of quality). The picture storage in JPEG demands a smaller place, than the TIFF format. The reason for this is that the JPEG format recognizes some data as unimportant and removes them during a compression. Moreover JPEG has one more advantage, you can control compression ratio, i.e. if you want to keep set of the images, having restricted space, and you can choose a compression so that the images fill in a free space completely. All this has resulted that this format became most popular at Internet activity if you plan to create your own Internet page, this format is for you.

Work with photos - screen editing.

You may make your picture in black and white or negative, remove somebody off your picture or add to it. You can do this due to some computer programs such as PhotoShop, CorelDraw and many others. All these programs are created as well as for professionals and for beginners. They have easy interface they renew constantly, acquiring new picture edition possibilities. Software is included to the delivery complex of almost all digital cameras. Software allows displaying the entire photographer's creativeness

Picture's swap speed to computer is a very important factor. Today there are many quick ways for data swap such as 3, 5 floppy disk adapter for data reading from smart card using the floppy-disk or adapter for PCMCI card for portable computers. The last high technology is adapter reading data by USB port which allows reading the information for some seconds.

Some corporations plan to begin production of cameras with a plugwire under USB - port only.

As originally CCD - matrix was originally designed for video cameras, they work precisely in that format, which is required for a record and reading of the picture PAL or NTSC. Therefore there are no problems with a possibility of a digital soft copy review on the TV. – PAL plugwire for hooking up to the TV is included in a standard complete set of Olympus cameras delivery.

The majority of photos located on web- sites, is made with the help of digital cameras. The digital photo is one of the main tools for web-sites creation. To place a photo in Internet it is necessary to keep it in the GIF format or even better the JPEG format. After that, all that is necessary for you is the HTML editor, which is built in such programs as Word for Windows 98 or 2000 for example. At creation your own Internet - pages it is necessary to remembering that the snapshots should be compressed in order to take little place and to reduce load time.

The picture swapping from your hard disk on the provider's server of the is made with the help of FTP programs (file transfer protocol), which provides a preservation of the data in the binary code.

One of the most important advantages of a digital photo is the transmition capability from one place to another everywhere in the world. It means a capability to transmit a photo by E-Mail with the help of the standard programs such as Internet Explorer or Netscape Communications. It is necessary to compress those series of photos which you are going to send as they take a lot of memory place while transmitted

Apart from it, it is possible to send a photo through the mobile telephone. For this purpose it is necessary to connect the telephone with PCMCIA by a card pasted onto the portative computer, thus you can send a photo, fax, an E-Mail or connect to Internet. However, it is necessary to remember, that the half speed of data transfer through mobile connection makes about 9600bit/sec. i.e. the sending of 1 MB will take approximately 15 min.