Color Folio offer both 8 and 16 bit scans from our Heidelberg Tango drum scanner. Some people prefer 16 bit workflows on their files and there are some instances where there are benefits to 16 bit scans.
Below is a brief summary of what 16 bit scans are all about. For
more detail, please download our white
paper on 16 bit digital imaging.
In general, we believe that most images do not require nor benefit from 16 bit scans. In addition, we use specially edited profiles for our 8 bit scans which give us more control over tonal range than we can achieve using our 16 bit scanning software. If you are in doubt about which bit depth you need, please call us. We also typically will contact you in the event we think you would be better off doing a 16 bit scan and have not ordered one.
What is a 16 bit scan?
Bit depth determines the potential range of values that each pixel
in your scan can have. An 8 bit file from a scan has a maximum of
256 values for each sample. A full 16 bit file has over 65,000 potential
values for each sample. Note that all Tango scans actually take
place in full 16 bit mode, but normally the scan is truncated to
an 8 bit file when it is saved to disk.
What are the benefits?
The primary benefit to a 16 bit scan is that you can make repeated
adjustments to the image without risk of image deterioration. As
you make changes to an 8 bit file, you change the values of the
pixels. Doing so often depopulates values, creating gaps in the
tonal range, or bunches previously different values, reducing detail.
You can see this effect by looking at a histogram of the image after
making several changes. If enough gaps or spikes are created, artifacts
can appear, such as posterization or loss of detail. An
image which requires large adjustments may benefit from
a 16 bit scan. Note, however, that most images, even with a histogram showing many spikes/gaps will likely look fine in print.
Download our white paper on the 16 bit workflow to learn about our recommended techniques when working with 16 bit files in Photoshop.
Remember that the same resolution scan in 16 bit will be twice
the file size as it's equivalent resolution scan in 8 bit mode.
Scan prices are based on file size. You can reference our scan
prices as well as a resolution chart
showing the resolutions and file sizes for different film formats
in 8 and 16 bit mode.