Resolution, Pixels & Other Definitions
Digital
Digital is the process of storing information as bits of ones and zeros. With digital, a byte is either on (1) or off (0). The data can be compiled and stored on a variety of digital media and run on a computer. Digital copies are exact duplicates of the original without any loss of quality.
Resolution
Resolution is the amount of detail displayed in an image. An image with a lot of detail has a high resolution and an image with very little detail is known as having low resolution. The resolution of a computer monitor resolution refers to the number of pixels on the screen.
Here is the tricky part: The resolution of a digitized photo depends on: The resolution capabilities of the camera that shot the photo, the resolution of the scanners used by PhotoScanMan to scan the images and the resolution of the monitor that you use to display the images. If you make prints of your digitized images, then you must also consider the reolution capabilities of the printer.
Camera resolution: This is meaured in Megapixels. The detail is in the pixel, literally. Generally speaking, the more pixels your camera has the greater the detail of the resulting photos. That may seem great, but for most everyday pictures you may not notice much of an improvement. If you're taking a picture of someone sitting outside, you're going to get a perfect shot with a 5 MP camera. However, if the subject has a small tattoo with small print, it may be difficult to read the fine detail. In this example, an 8 MP picture will produce a much sharper image making it easier to read the fine print.
PhotoScanMan resolution: We give you a choice of having your image scanned at either 300dpi or 600dpi. Images that are scanned at the higher resolution can be enlarged up to three times its original size and still maintain high quality image. However, scanning at a higher resolution takes up more space on a CD, computer or external flashdive. Most families scan there pictures at 300dpi.
Monitor resolution: Today are generally set to display at a resolution of 1024 pixels by 768 pixels. Users can manually adjust the monitor to as low as 640 pixels x 480 pixels, or as high as 1280 pixels by 1024 pixels. The higher the resolution, the more data can be displayed on the screen and the sharper the image
Printer resolution – The terms dpi and ppi are sometimes used interchanged. DPI refers to the number of dots per inch. The more "dots" you have on a printed page, the sharper the image because there is more digital information available to process. PPI refers to the number of pixels per inch and is often used by graphics professionals to measure resolution.
DPI
The term dpi refers to dots per inch. DPI is a common method of measuring the resolution of information being digitally captured. When you scan a photograph for example, the scanner creates the number of dots based on the resolution setting. A 600x600dpi image will have 600 dots per inch. In order for you to see the image on your computer monitor, a graphics card will convert the dots into pixels so that it can be displayed on your computer monitor. PhotoScanMan scans photo prints at 300dpi and 600dpi and 35mm slide scanning at 2000dpi and 4000dpi. This will give you an idea of how the resolution compares if the pictures were taken with a digital camera.
Pixel
While dots are used to measure printed resolution, pixels are used to display video images. Each pixel carries a bit of data about the image. The graphics card in the computer processes these pixel values to display the image on your computer monitor Nobody really had ever heard of mega pixels until digital cameras became widely available. Let's say you have a 4×6 color photo print that will be scanned at 300 dpi(dots per inch). So the photo is 4 inches by 6 inches. Scanning at 300dpi means 300dots X 4 inches and 300 dots X 6 inches. This will result in a 1200 x 1800 pixel image which is 2,160,000 pixels or 2.1 MP for short. Each pixel contains three bits of data, one bit for each of the primary colors red, blue and green. Each bit holds a number from 0 to 255 that correspond to the RGB color scale. The RGB code for black is 0-0-0 and the RGB code for white is 255-255-255. When you put this puzzle together you get a complete image. Obviously, the more pixels you have the bigger the file. To calculate the file size you take the number of pixels and multiply by 3 because each pixel contains three bits of data. In our example above, a 2.1 MP image contains 6,480,000 bits which equates to a 6.32 megabyte file. Since a standard DVD can store 4.7 gigabytes of data (there are 1,024 megabytes in a gigabyte), each disc will store 761 of our 4×6 images at 300dpi.
Megapixel
There are one million pixels in one megapixel. Since digital photos are displayed on a video monitor built in to the digital camera, screen resolution is measured in pixels. The more pixels you have to display, the higher the resolution. A higher resolution photo is much sharper which makes it easier to see fine detail in an image. For example, a 7 mega pixel camera is able to capture roughly 28% more detail than a 5 mega pixel camera taking a picture of the same image. How does a digital 35mm slide scan compare to 35mm film? A standard 35mm shot on slide film contains approximately 20 mega pixels of data. Therefore, scanning your 35mm slides at 4000dpi will give you quality that are very similar to film.
VHS Video Cassette
When VHS was introduced in 1976 it quickly became the defacto standard video tape for its ease of use, long recording times and high quality. Still today, VHS is commonly used in many to record movies and television programs at home. The maximum recording time is 6 hours.
Super-VHS Video Cassette
Super VHS is a hi-fidelity version of the standard VHS video tape providing more saturated colors, higher quality sound and improved stabilization. The maximum recording time is 2 hours.
VHS-C Video Cassette
The VHS-C is a smaller version of the standard VHS video tape for camcorders. Using an adapter, the VHS-C will play in any standard VHS video player. The maximum recording time is 90 minutes.
Video8 (8mm) Video Cassette
Do you remember the HandyCam? In 1985, Sony introduced the HandyCam for the amateur video market using a compact Video8 tape (8mm video). The Video8 tapes became attractive because they were smaller than the VHS-C. Video8 became the preferred recording format for both amateurs and professionals. The maximum recording time is 2 hours.
Hi8 Video Cassette
The Hi8 video tape was introduced to compete with the VHS-S video tape. Hi8 offered improved picture quality and hi-fidelity over standard. The major drawback was that while video8 tapes played in Hi8 equipment, Hi8 tapes are not compatible with standard video8 machines.
Digital8 Video Cassette
The Digital8 video cassette is an 8mm video tape (Hi8) in which the video signal is recorded digitally on the video tape. The maximum recording time is 135 minutes.
MiniDV Video Cassette
The MiniDV is a smaller version of the Digital8 tape. MiniDV cassettes use ¼" magnetic tape with metallic particles that provides the highest quality of digital video recording and playback for consumers. Also, copying from one MiniDV to another can be accomplished with very little loss of quality. The maximum recording time is 83 minutes.
