Preservation of colors and of image details is one of the objectives of photo scanning. Not only do we want to preserve images as they are now, but also as they originally were captured. Photo prints, slides and negatives all experience some degree of color shifting over time. This is especially apparent in cases where in amateur film stocks of the 1960s and 1970s or when cheap photofinishing was used. It was not uncommon for mass-market photofinishers to skimp on quality control to achieve ultra-cheap mail-order or drugstore prices. Photo prints looked okay when they first arrived in the photofinishing envelope, but faded over the years.
Today’s film development process, called C-41, is very stable, meaning a properly finished color negatives retains its color accuracy for decades, if they are stored in a cool, dry place. Prior to 1972, the common color-negative film process was called C-22.
Photo prints are made with a process called RA-4. This process produces long-lasting prints -- some paper manufacturers claim a hundred years before visible fading -- if prints are stored in a cool, dry place. Sunlight and radiation are the enemy of the dyes used in most photo processing, and can affect color in long exposure. Putting valued pictures on display in frames with UV-resistant glass can prevent fading.
The two most popular slide film processes, E-6 and Kodachrome, provide long life and retain their color fidelity more readily than prints.
Why then, do colors on our computer monitor look different than prints? There are many technical reasons, including the fact our eyes respond differently to reflective images (prints) compared to a backlit monitor. If the accuracy of colors is important to you, then consider using “color management” to bring it all together. Color management is a system to unify the colors you see on your screen with prints.
Color Management Systems
Color-management systems used to be used only by professional photo labs and graphic artists, but now there are affordable desktop techniques. For most people, simply calibrating your monitor will be sufficient. The simplest calibration methods involve adjustments to the Contrast and Brightness settings of your monitor. Make sure your monitor is in 24-bit or high-color mode. Use normal room lighting and avoid reflections or glare. Find the Contrast and Brightness controls on the monitor; these will either be buttons on the front or on an on-screen menu to make these adjustments.
Using the menu, set the color temperature - also known as white point - to 6500K; another alternative is to select the sRGB color space. Choose one of your prints that has a range of colors you prefer; if you want a more advanced and technical solution, there are sample files like the Gretag Macbeth ColorChecker you can use to adjust your color.
Using the Contrast and Brightness controls, adjust the monitor so the various shades of gray plus bright white and black match the your sample print. For many users, a few simple contrast and brightness adjustments are sufficient.
An intermediate method uses special software to calibrate the monitor, a printer, a scanner or other devices so images will look similar. ICC profiles are specific to each device and contain information about how that device produces color. Tools for calibrating monitors, scanners, printers, and digital cameras use ICC profiles so all these devices use the same “language” to describe color. With software calibration, there are similar on-screen menus as described above, but that are much more detailed. There is also a “generic” ICC profile that may be suitable for many users.
At the high-end, hardware-based calibration uses light monitoring and measurement devices to achieve the more exact results. The devices read the light in a room and adjust the monitor accordingly.
Photo scanning services can take the guesswork out of scanning photos - don't miss using FotoBridge's newest coupon code for your next order!
Photo Credit: Flickr