The scanner resolution determines image detail of the source photograph. The higher this factor is, the more accurate the image will be, but the larger the size of the output file will be as well. One of the most common mistakes is that some users tend to increase resolution in the hope of getting the highest-quality scans. But it won’t work. Each scanner has its own absolutely definite physical capabilities expressed by its optical resolution as well as interpolation, i.e. camera resolution is indicated.
Optical resolution shows the size of real information of the scanned object, whereas interpolation is a software algorithm which does not add any new details to the image. In this case, the value of color and the gradation of grey are averaged according to the parameters of the nearest pixels and a new, generated by the program pixel is inserted between them. This doesn’t improve the quality of the picture but smears it. Resolution can often be indicated by two numbers in the specification of a scanner, e.g. 1200/4800 dpi. The first number shows that the optical resolution is 1200 dpi, the second one is based on the method of interpolation unnaturally creating an additional volume of information. Do avoid interpolation and never scan with a higher resolution than the optical one!
There is no doubt that you are only interested in optical resolution. I recommend specifying scanning resolution as no less than 300 dpi or 600 dpi. If you are planning to enlarge the original image, you should make use of the maximum optical resolution of the scanner, e.g. 1200 or even more. It is very important to choose the right resolution of your future file, as it is necessary to get as many details of the original photo as possible, which may have a profound effect on the subsequent editing of the image.
I hope everything concerning the scanner resolution has been clarified and this important feature won’t cause any problems in future. OK?
Now, it is time to find out which type of the original photo is to be digitized. The following three variants are the most common - Reflective, Transparent and Negative. As a photograph is to be scanned, we choose the reflective one. We also set the mode of operation of the scanner. From the opening list - Line art, Grayscale, RGB Color, CMYK Color – we choose RGB Color, even if a black-and-white photograph is to be scanned. You might ask me why. The answer is simple enough. We need to get as much information about the original as possible, especially if we are in for a lot of restoration work. Literally, it is each pixel that matters here. So we should choose RGB Color scanning mode whether it be a color or a black-and-white photo.
There is one more feature which you are sure to come across in the scanner’s menu options, it is Color depth or Bit depth. To put it simply, this characteristic is responsible for the color sensing of the scanner, i.e. for the ability to distinguish and reproduce the total number of initial gradations of the color or color shades of grey of the source photo. 24-bit color of the RGB format is considered to be standard, 8 bits for each of the three color channels – red, green and blue.