●Printing problems and instructions on shooting

The properties of pictures taken by digital cameras mean they have a detrimental influence on printing. They include ghosting, flares, smears, color saturation, and white balance accuracy. Camera manufacturers are attempting to counter these influences by taking a range of measures. The type or degree of influence depends on the camera grade.
There are differences between digital cameras and film-based cameras, especially in terms of focal length, angle of view, CCD size and depth of field
Digital cameras with a small-sized CCD have a large focusing area, that is, great depth of field. In contrast, digital cameras with a large-sized CCD or 35mm film-based cameras have a very small focusing area. They provide an image that is clear in its area of focus but is blurred elsewhere. However, there are many cameramen who take pictures making use of the small depth of field to obtain images with clear foregrounds and blurred backgrounds.

Digital cameras are generally provided with a digital zoom function. However, photographers who use digital cameras need to be aware that this function generally decreases resolution.
Digital cameras are also equipped with highly useful liquid crystal monitors. Conventional compact cameras have only optical finders that give an incorrect field of view. The liquid crystal monitors mounted on digital cameras, like single-lens reflex cameras, give a correct field of view. Thanks to these monitors, therefore, photographers can correctly confirm their shooting areas even when using low-priced digital cameras. However, liquid crystal monitors have two disadvantages; they don't have the capacity to check colors, and they are ineffective under dark conditions.

In a digital camera, the white balance has a color tone changing effect, which is similar to replacing one film with another in a film-based camera. Recently, standard digital cameras have employed the Exif format. If a photographer uses a digital camera with Exif format, he or she will be able to know what white balance is used after taking a picture. The photographer's intent is revealed depending on whether the white balance is set in the manual, automatic or other mode. If the white balance is set in automatic mode, a digital camera may succeed in providing the image that the photographer desires, or it may fail by selecting a white balance that gives an undesired color cast.

●Instructions on data delivery

In discussion with the representatives of digital camera user groups and printing and plate making companies, we are now preparing a reference book and brochure on future digital data and RGB data delivery methods. We want to prepare a data delivery format. To do this, the following items are under discussion:

• Function of providing information about the formats and data sizes of the delivered files. This function will check whether or not compression or processing is used.
• Processing / non-processing, and the name of the file creation software. What software is used to create a file? The file receiver requires the same application.
• ICC profile.
• Setting the lighting conditions and white balance. These indicate the shooting technique. The intent of the photographer is unknown if digital data is processed automatically, unlike the case with film, which may be evaluated by a human operator in the course of processing. Therefore, it is necessary for some input to be provided to know what is intended, which can be determined by the selection of the white balance.
• It is necessary to tell the system what the subject is, and what the photographer's intent is in creating an image of the subject.
• Color samples. They provide information about the intended colors to plate makers and printers. Some question the necessity of color samples when digital cameras are largely used. If color management is introduced in the appropriate environment, color samples are not necessary. In practice, it is safe to use color samples because there is no ideal environment.

At present, plate makers and printers may receive raw data. Raw data can be recorded by middle- and high-class digital cameras, meaning unprocessed or raw images. If plate makers and printers receive raw data from a photographer, they have insufficient information about his artistic intent. An application specific to a digital camera is required to open the file of raw pictures taken by the camera. The plate maker or printer receiving the raw images does not always have the application applicable to those images. Therefore, plate makers or printers should not receive raw images.
If the file of image data provided by a digital camera is received, it is necessary to confirm all the attributes of the data file. Is the color space in sRGB or AdobeRGB? Compact digital cameras generally use the Exif format, and it is easy to ascertain if the color spaces of images provided by the camera are in sRGB. If photographers use middle- and high-class digital cameras, they may specify the appropriate profiles as well as a wide range of colors including AdobeRGB.
If the received files of image data are opened incorrectly, the images may be reproduced in the wrong colors.

It is important to confirm the file format used. Are the data raw or retouched? If a Photoshop file in TIFF format is received, it is obvious that this file has been retouched using Photoshop. Therefore, it is important to check the resolution used and color space (AdobeRGB or sRGB) using Photoshop.

●Digital camera data delivery and the future workflow

Where and how should the RGB separation (CMYK conversion) be made?
Photoshop is generally used for RGB / CMYK conversion. But what are the proper settings for Photoshop? Is Japan Standard V2 or any other profile used? A prepress maker is selling ColorGenius, and company F is supplying a special color separation application for digital cameras. Any of these applications may be used, depending on the preferred method for adjusting colors to meet client needs.

There are a variety of digital cameras. Who should guarantee that excellent images are obtained from digital cameras? How should this guarantee be given? One effective solution is color management. If a profile is prepared for each camera, it cannot cover many cameras at all. It is not realistic to provide thousands of profiles on demand. A common solution would be to use the AdobeRGB or sRGB environment. It is a serious question as to whether or not this solution would be satisfactory.
Cameramen told us that they wanted to actively use digital cameras. This means that digital cameras have the greatest benefits in terms of cost and time.
Digital cameras are expensive, but are economical to use because they do not use film. Consequently, RGB data will be routinely delivered to plate makers and printers. Some cameramen carry out color separation of their images by themselves and deliver the 4-color data to plate makers. In most cases, plate makers and printers will process RGB data.
Plate makers and printers are receiving more and more RGB data, though they are still at the stage of trial and error and the handling of RGB has not yet matured. An important problem that needs to be addressed is how to manage RGB properly.

2004/11/30 00:00:00