DIGITAL PHOTOGRAPHY-THE BASICS

HARDWARE

Cameras

Digital technology forms an expanding branch of photography, but cost is still high for higher resolution equipment. Generally the higher the number of pixels ( picture elements ) the better. Figures of 6+ mega pixels (millions of picture elements) are now common and prices are dropping rapidly. However quality of the lens and construction of the camera should also be considered. High pixel values are required to even approach 35mm photographic quality on an 10x8 inch photograph( 35mm film is equivalent to 11-40meagapixels). This will also require access to a computer with adequate processing resources and a good printout. Digital cameras are good for general work and photographs to be used on the Internet, but for the highest quality, conventional photography is still best, however for many people digital has many advantages. Images can also be input from some video cameras and players equipped with suitable hardware and software.

Scanners.

Flatbed scanners are a common method of making digital files of photographs, text, diagrams and even small three-dimensional items. They are fast, cheap and easy to use. They are capable of resolving fine detail, but file size can be very large. The output is shown in dots per inch (dpi) with a variable range of 70-4800+ dpi. 70 -150 dpi being used for screen and most printer applications, 300+ for fine work. At higher dpi the file may be 100 or more megabyte for an A4 sheet. A fast computer with the means to store large amounts of information is required. Some flat bed scanners can be used to scan films (negative or positive) with varying degrees of success.
Film scanners are specifically used to scan film or transparencies. Resolution is high 2 000 - 5 000dpi. However cost is generally higher than flat bed scanners. Again file sizes will be very large. Many of the most recent scanners offer film scanning attachments. The high priced scanners can now produce scans near to dedicated film scanners in quality. They are good enough for most peoples purposes and can also scan large negatives and transparencies.

Memory.

Large amount of RAM (random access memory) measured in megabytes (or meg) are required for fast effective image handling in order to keep processing times short, Faster memory types are best.128 megabytes are minimum requirements together with a fast graphics card with 32 megabyte or more graphics memory. CPU (central processing unit) the faster units are best for image processing- 300-3000Mhz+ are now available, slow speeds and low memory can make processing for large files painfully slow.The more memory the better (Ram and hard disc space).
Files .
Documents or photographs are stored as files. These can take many forms. Different types of files have different properties, allowing additional information to be stored for future use of the file. You can tell the type of file by the letters after the file name (called the extension), for example name. bmp or name. jpeg .

Raw- this is fast becoming an industry standard. Raw is (almost) unprocessed information from the camera. It contains all the information and can be endlessly altered. A processed copy can then be made for further work in photoshop or printed out. The information in the raw file is retained.
BMP -standard windows and dos format. Use for lower resolution images.
JPEG -Joint Photographic Image Group used for most photographs and continuous tone images. JPEG supports various colour types and gray scale. A JPEG is saved as a compressed file but is automatically decompressed upon opening. Image files can be greatly reduced in size but still show good quality. This makes then ideal for the Internet use of photography.
PDF -portable document Format is used by Adobe acrobat. This is often used for downloading information but needs to be opened in Acrobat. It supports CYMK, RGB colour and gray scales.
TIFF -tagged image format is a flexible image format supported by most paint and image editing applications. It supports CYMK, RGB colour as well as Grayscale.
PSD - Photoshop document retaining most of the information without degrading the image.

Various others exist, often produced by particular programs. Most problems occur when opening a file in another format. So make sure any application you intend to use a file in, supports it. Often you can save programs in different formats (file-save as-save as type). Files may also be imported into another document.
Files storage. . The various types of file are stored by different methods. On the computer files are stored on the 'Hard' disc or drive with other programs and the computers operating system. Very large sizes are now available (60-200+ Gigabyte) allowing vast amounts of data to be stored, however you will still require portable data at some time. Small files up to 1.4 megabyte can be storage on a 'Floppy disc' . Larger files can be stored on other hard discs inside the computer, or as external drives. Files may also be written onto writeable CD ROM . This allows up to 650 megabytes of information and is useful for large images. Writeable DVDs are now becoming available and are able to store vast amounts of data.
Other methods are small portable 'zip drive' with small 100 or 250 Megabyte discs; also the Internet offers storage facilities for a small a charge or sometimes free of charge. Rapid access and safe backup are important considerations for file storage. Flash drives which plug into a USB port are cheap, easy to use as well as being hardwearing.

Printers.

Good cheap colour printers are now available. Most are now the inkjet type with excellent results. inkjet alignment is very important for the best results. Different types of printing paper are available and greatly affect the quality of the final results. Again resolution of the image is in dots per inch (720-1400 dpi are now common). Some printers will print directly from a digital camera. Although printers are now inexpensive the ink cartridges often make up for this. Check out price and availability when buying.
Paper quality is important and photo quality paper is almost as expensive as normal photo printing paper. The printer manufacturers own paper is a good place to start. Paper weight indicates quality-180-300gsm for photo quality. Many surfaces are available-adapt to suit the subject.

Software.

Some related software is supplied by the relevant manufacturer, other software may available as free-ware (no cost) or share-ware (low-cost) from the Internet or other sources, recent editions may be far cheaper than the latest release. Demos of most software are available, try this before spending large amounts of money on the latest upgrades with features you may not require. Also try to use software specifically designed for your purposes.See also software image manipulation software

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