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Information sheets on design, illustration, digital imaging, photography and other related topics. Compiled and written for my clients, students, and my own work. Provided here for your convenience. If you take information form these sheets to use elsewhere, please provide the appropriate credits along with the information.
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Photography is more art than science. Digital photography adds techniques to photography that were difficult or impossible to achieve before the advent of sophisticated computer systems. They do not produce miracles, although it sometimes seems that way. Absolute guarantees are not possible in any aspect of life. Digital photography is no exception.
The photo must be converted into digital form, adjusted and manipulated in the computer and transferred to the print medium or used to expose photographic film. There are many diverse methods for doing this. Each stage has its own unique requirements. All stages and equipment must be calibrated and coordinated to achieve the results desired.
By necessity, the digital imaging process is based on complex expectations and desires translated into words and interpreted by several individuals. Misunderstandings and omissions are to be expected. For this reason examples, where possible, and an on-screen viewing session is a critical part of the process.
This process often requires much time in discussion and experimentation. Much of this time is not "billed directly" to the client. If extensive changes and revisions (author's changes) are requested they may require additional charges. On rare occasions it is not possible to achieve the desired results. Cancellation or rejection of the work at any stage will require reimbursement of all expenses incurred to date and a prorated fee for time spent.
The final results of any digital process are influenced by many factors: the various types of equipment used, the skills of the operator & technicians, the type of output, and the type, condition & color range of the original.
Every digital printing device has its own range of color, contrast and detail capabilities . Images designed for one device will look very different on another.
No direct digital output device today can accurately proof images intended for photographic printing.
Images scanned or converted to the CMYK color space for offset printing (very high contrast, limited color range) are usually not suitable for output to photographic film (a lower contrast, more detailed, continuous tone, RGB color range).
Subtleties and accuracy of color are influenced by the device's grayscale step range and the lines per inch of the output. The "gray scale" or total number of shades from black to white a device can produce, and the number of lines per inch it uses to produce the image. This has more influence on the quality of the final print than the dots per inch of ink or toner.
Most Laser printers and non-Postscript devices use between 16-64 shades of gray. Postscript devices currently top out at 256 steps. Newspaper is printed with a line screen around 85 lines per inch (lpi). Most offset press is done with line screens between 100-200 lpi. The average imagesetter is capable of 2500-5000 lpi. Photographic film is capable of millions of steps. Digital photographic film may range from 2000 - 20,000 lines per inch.
Black and white digital film (usually TMAX) is very straight forward. Slides and color transparencies (E6) benefit from having a good quality sample for the operators to use as a match. Some colors are difficult to reproduce with accuracy: subtle shades of green seem particularly difficult in digital film. The color and density of color negative film (C41) will vary from time to time and machine to machine, just as it does in photographic prints. Many service facilities no longer produce digital color negative due to the difficulty in correctly balancing the process. Internegatives (photographically produced copies) can be made from color transparencies. Detail in negatives can be evaluated with a photographers loop but a sample print or digital viewing machine (available at some photo labs) is necessary to judge color and other aspects.
Communication is the most critical factor in any creative process. Every imaging job is unique. Requirements and results are "in the eye of the beholder." We all wish to produce an outstanding image that is appropriate for its intended use. A satisfactory result depends on good communication at every step. Elements that seem "obvious" to one person may not be to another. Unforeseen situations are to be expected. Please feel free to ask "dumb" questions at any stage. If I cannot provide an answer I will be happy to help us both find one.
For additional information on industry and trade standards see Welcome to PINC
Thank you considering our services and we look forward to a pleasant, productive working relationship.
Sandra Ragan ©1999
* hardware and software
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