Deciding on a file format for scanned negatives depends on your later use of them.
Scanning negatives is the best way to preserve them and keep them from damage such as scratches and blotches. You still need to protect your negatives in case you have a hard drive crash, but once you have them on a hard drive, your negatives will appear as pristine as the day you scanned them. You need to make choices for there storage format, however, depending on several key factors.
TIFF 16 Bit
If you are a professional photographer or a very serious amateur photographer, you will want to save your scanned negative files in one of the best quality formats possible: TIFF 16 bit. TIFF, which stands for tagged image file format, does not compress images. This means you will not have to deal with visual noise or other problems associated with compressing image files. TIFF 16-bit images hold the most information in digital format, other than RAW, when shot by a high-end digital camera. For maximum quality, do not choose a compression option when saving to TIFF. One downside of TIFF 16-bit images is that they are large files. They take up a lot of room on a hard drive. Still, if the highest quality for your scanned negatives is important to you, choose TIFF 16 bit.
TIFF 8 Bit
The next step down is the more standard TIFF 8-bit format. As long as you do not compress the files, TIFF 8 bit will suffice for most storage applications. You still will get high-quality prints from this format, and most publications such as newspapers and magazines use it for this reason. It also prevent visual noise from appearing in scanned images, and each file still takes up significant hard-drive space, though less than TIFF 16 bit.
PSD
Many photographers work with Adobe Photoshop to edit and improve images. One advantage of this is the ability to use layers to adjust the images and add special effects. Once you add layers, you need to save your digital image files in either TIFF or Photoshop's PSD format. Even when scanning your negatives to store, if you intend to use them in Photoshop, save them in PSD format. It retains all the digital information available, just like a TIFF.
JPEG
Most amateur photographers and those with a limited hard-drive capacity choose JPEG to store their images. If a digital scan of a negative is 17 megabytes, for example, saving it as a JPEG reduces the size to approximately 4 or 5 MB. So, if you need to store a lot of scanned negative files but conserve space, JPEG is the right format. However, because it compresses your digital images, you may notice residual visual noise such as red-green-blue spotting in your images, especially if you make big enlargements from them. Professionals rarely use JPEG for this reason.
