3. Scanning equipment
The hardware device that must be used to scan separations is the scanner. The scanner is an optical, mechanical and electrical integration high-tech product and an important tool for inputting various forms of image information into a computer. At present, the color scanning input device based on the dot-photocell technology can provide a high-precision level with a resolution of over 8000 DPI, and at the same time can read a wide range of gradation values ​​in the relative density range of the document of 0.0 to 3.8. These techniques allow the original to maintain its natural and realistic desired effect during input and reproduction.
In general, the scanner includes four parts: a scanner head, a main board, a mechanical mechanism, and an accessory. Among them, the scanning head (plane scanner) is composed of CCD photoelectric coupling devices, the accuracy of which directly affects the degree of restoration of the scanned image; the scanner main board includes a central processor, an analog-to-digital converter, an interface, etc., and mainly completes the image data. Conversion, computer interface and other functions, it controls the entire working process of the scanner. The scanner has two working modes of reflection and transmission. They are used to scan color photos and transmission originals respectively.
The current market for scanners is dominated by several major brands: Epson, HP, Canon, Microtek, and Hanyi. Since ordinary color scanners are common, they are used in everyday office and will not be explained here. The following will focus on film scanners.
3.1 Understanding Film Scanners
The film scanner is different from the reflective flatbed scanner used for scanning paper documents and photos that we use every day. Although it is also based on the CCD sensor like the flatbed scanner, its scanning principle is the projection method. It uses Higher sensitivity sensor with higher resolution. Therefore, it can more ideally digitize small-size transmission originals. The film scanner has a wide enough dynamic range to enable it to capture the full range of tonality of a typical transmissive document. The image on the film is truly and fully restored.
For now, film scanners can be divided into two major categories: professional pure-film scanners and flatbed scanners that can perform film scans by installing a transmissive adapter (TMA).
The professional pure film scanner works through the principle of projection and imaging of optical components. It has the characteristics of small size and light weight, and the price ranges from 5, 6,000 yuan to tens of thousands of yuan. Because the price is more expensive, it is generally used in publishing, advertising production, professional photography and other fields.
Flatbed scanner with film adapter mounted on the Transmissive Adapter (TMA): This type of scanner was originally imaged by reflection, but the direction of light reflection was changed by installing a transmissive adapter to allow it to scan the film. . However, due to the influence of its own resolution, the scan quality of such scanners is not high. As a home user, some quality scans are not required.
3.2. Talk about film scanners
The purchase of a pure film scanner is different from that of an ordinary flatbed scanner.
1. Higher resolution requirements
At present, ordinary flatbed scanners have a very high professional-grade resolution of 2400 dpi, but this is less than the starting point for film scanners. The resolution of the film scanner can basically be divided into two grades: 2700dpi and 4000dpi. 2700dpi is the entry requirement for professional pure film scanners. At present, the resolution of most professional pure film scanners is 4000dpi. This is why film scanning using a flatbed scanner equipped with a TMA is an important reason for poor film scanning.
2. Learn about supported scan format types
Unlike the flatbed scanner's scan format logo, a pure film scanner should understand the different film models it can support. Although the most commonly used is 135 film, there is no shortage of other types of film. Therefore, as many film support models as possible will bring convenience to your use.
3. Software function plays a key role in the scanning effect
Compared to photographs, films are more prone to wear and dust, and the high resolution of 4000 dpi can show them off. In this case, it is very time-consuming and laborious if the user is to manually eliminate these defects. Therefore, the pure film scanner must have the function of automatic mark removal to ensure the quality of the scanning.
The above three points are the most critical for purchasing pure-film scanners. In other aspects, users can choose through their actual application.