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DATA: RESOLUTION page 1 of 3 |
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| plum grafik visual arts & communications sandra ragan |
sandra@plumdigital.com
www.plumdigital.com |
This three page article is intended as a guide and visual reference for novices and professionals. Links to other recommended books can be found in the Library,
As mentioned elsewhere, any photo or "hard copy" image must be converted into digital form before it can be adjusted and manipulated in the computer and subsequently transferred to the final out put medium. 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. 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. Determining resolution for input and output is never straightforward. There is not enough room her to discuss all the possible factors. The nature of the original, the work that needs to be done and the intended use are just a few of the factors to consider. Return to Plum Data Sheets In general web images need to be as small as possible. Images for desktop printers need to be fine-tuned to each individual machine and paper stock. Both web and paper need high contrast images with sharp edges and crisp colors. Images intended for photographic film need a very wide "dynamic range," meaning they need to have much more subtle transitions from tone to tone. The more "steps" between black and white, the more detail you have and the smoother the gradations are. The original for the type sample is on page three.
In this sample (scanned at 72 ppi - actual size on the left and magnified 200% on the right) the software is attempting to provide transitions between light and dark areas, like its interpretation of the original. This has smoother blends than the images below but less detail.
In this sample (scanned at 1200 ppi, displayed as large as possible and screen captured at 72 ppi on a 17" monitor in 32-bit mode at 1024x768 on the left, and magnified 200% on the right). This is similar to what you would see in a sharpened drum scan. This image has more detail - look at the paper grain detail, but the contrast on the text makes the edges too jagged to read clearly. Which one is better? It depends. Neither if you want to read the text. And what YOU see as you are looking at this depends on the equipment YOU have. Send it to your printer and it will look different than whet you see. In this case you might want to combine the two in a simple one-one overlay, the soft image on top set to 100% Multiply.
Further fine tuning is still necessary, but you can see the difference that something this simple can make. Sandra Ragan © 1999 Continue to the Resolution page 2 Return to Plum Data Sheets Return to Design & Digital Imaging, Retouch , Computer or the Portfolio |
