Digital Image Quality can vary enormously depending upon various factors. The first in this chain which determines the quality of your captured image is the image sensor in your camera. Many Camcorders now sport digital photshot (the word probably coined by Panasonic for their eminent range of camcorders) in which still shots are saved as well. The higher is the resolution in the image sensor, the better will be the final image quality. As we have mentioned earlier, it is just one of the factors.
The light and the angle in which it strikes the subject, the color of the light, the reflective properties of the subject, the exposure settings and the back light form some other links in this chain. As each factor affects the overall image quality, it would be better to start off with the highest quality possible under most of the conditions - if they are under your control.
Most digital cameras save some essential details about the settings in a standard format which can be read by machines and software. EXIF Exchangeable Image File Format: a standard for storing interchange information in image files, especially those using JPEG compression. Most digital cameras use the EXIF format to display information like
- X resolution
- Y Resolution
- Component Configuration
- Color Space amongst others.
As in TV, picture quality or picture resolution is always measured by an objective method. In TV parlance, picture quality is measured in terms of lines. While the standard NTSC (American color standard) has a resolution of 525 lines, the European PAL color system has 625 lines. In our case - digital photography, the resolution is measured in pixel - short for picture element.
The more the number of individual picture elements the better is the quality. A film may boast of much higher resolution and dynamic range than a digital camera, but slowly the films are losing ground as technology advances. Typical mobile cameras offer VGA quality or 640X480 (height multiplied by the width of the image) resolution or about 307200 pixels, (or .3 mega pixel) which is more than adequate for sending your images by email or posting it to websites. Typical small digital cameras offer 3 mega pixel resolutions and some cameras offer even 7 mega pixel or more resolution. But it all depends on the situation and the need.
The following chart shows the approximate pixel resolution and the need along with the probable file size:
The file size can vary from one shot to another as it depends on the details captured.
|Print Size||Pixel||File Size
|Web Use /Email / MMS || 1 mega pixel ||50 k typical |
|4 x 6 inch print ||3 mega pixel || 70 -120 k |
|5 X 7 inch print ||5 mega pixel || 120 - 800k |
|8 x 10 inch print ||7 mega pixels || 800 - 2200 k |
|11 x 14 inch print ||12 mega pixels || 2200 k - 25000 k |