Before developing your Submissions Guidelines, carefully evaluate your needs and decide on a consistent policy for instructing photographers how to prepare digital files.
The following are key elements to address. After you have chosen the options that fit your business, you can use our Guideline Generator to prepare a document that contains your own custom Digital Image Submission Guidelines.
Color Management
Both suppliers and receivers of a digital image file need to see the same image. This requires setting systems to display color in a standardized and consistent way, and embedding color profiles in images as a means of describing their color characteristics.
File Size and Resolution
File size depends on the intended use. As a rule, stock image distributors require the largest file sizes, since final usage is unknown. Magazines can be more specific, although they may request Double Page (11 x 17 inches, A3 or 420mm x 297mm) for maximum flexibility in placement and cropping. Graphic designers and advertising art directors should be very specific about file sizes, since it’s best for the photographer to deliver files within 10 percent of final size — unless the designer will handle resizing and output sharpening. If designers do resize images, it is best to start with a larger size and reduce it, rather than attempting to increase the resolution of smaller files. Web use and digital projection require much smaller file sizes. Widescreen HDTV requires 1920 x 1080 pixels for uncropped images.
File Formats
In most cases, the choice of file format is between uncompressed TIFF or JPEG (Photoshop quality 8 or higher). Both are standardized formats, universally supported by image editing and cataloging software, and both safely hold metadata.
File Delivery
Regardless of format, file extensions are essential for cross-platform transmission. If images are delivered on CD-R or DVD-R, request them recorded in ISO 9660, cross-platform format. A portable hard drive may be the best tool for delivering large numbers of files, but beware of compatibility issues between Macintosh and Windows file systems. Online delivery via email, FTP or a commercial web delivery service offers an increasingly attractive and viable option. Compressing folders of files in digital wrappers, such as ZIP or SIT archives, helps insure against file corruption. UPDIG recommends requesting “ReadMe” files with all delivery media and methods to describe file characteristics and usage rights.
ICC Profiles
The two primary color modes in use, RGB and CMYK, each offer many flavors. In general, RGB color is more user-friendly and flexible. It also produces files at a given resolution and bit depth that are about 25 percent smaller, since it has three channels to CMYK’s four. Each RGB or CMYK variation has pros and cons. Always specify color profiles be embedded, and always preserve embedded profiles when opening digital image files. These steps go a long way toward preserving a file’s color.
Sharpening
After resolution and color, sharpening can have the most impact on perceived image quality. Most digital cameras deliver slightly soft images (unless the capture_format is set to JPEG or TIFF with in-camera sharpening turned up). This results from the almost universal use of anti-aliasing filters to combat moirŽ. Scanning camera backs and some medium-format backs - especially those able to work in multi-shot mode may not have this feature. If we assume single-shot RAW file capture, it is entirely appropriate to request a small amount of default “capture” sharpening. Without it, digital image files may look too soft.
How and when to add process sharpening and sharpening for output requires clear communication between those requesting digital files, and those creating and delivering digital image files.
File Quality
Too much pixel editing of color and tone, as well as over-sharpening, can easily lead to image-quality issues. Use high-quality scanners for film originals. Note that the quality of the scan depends as much on the skill of the operator as on the technology employed. You may want to address these issues in a digital-image submissions guide, and even provide some examples of unacceptable file-quality problems. Digital images prepared for commercial printing should ideally have RGB output levels set between 3 and 253 to ensure a halftone dot with a smooth transition in the highlights, and avoid a loss of detail in the shadows.
File Naming
To avoid problems with files transferred across computing platforms, request file names that use only the letters of the Latin alphabet (A-Z, a-z), the numerals 0 through 9, hyphens and underscores. Avoid other punctuation marks, accented vowels, non-Latin letters or other non-standard characters, such as \:/*<> or brackets. On a local network or with rewritable media, limit the file name to 31 characters or less (including the three-letter file extension. Limit file names to 11 characters or less (including the three-letter file extension) when burning to optical media, since some computers may not support long file names. Use a single period (“.”) between the file name and extension. Specify unique file names. Multiple files with the same name will cause problems for computers and people alike, and a newer file might automatically overwrite an older with the same name, or vice-versa. You may want to specify including the numeric date and/or the name of the photographer as part of the file name as a way to avoid duplicate names.
For a complete guide to file-naming protocol, see the Controlled Vocabulary website.
Stock image distributors have the greatest need to implement their own file naming conventions, followed by magazines and publishers.
For image-file tracking, it’s a good idea to ask image creators to include their original file names in Document Title fields (of images’ metadata), since many end users change the names associated with files.
Metadata
Digital image metadata, an increasingly important attribute, is information about images included in digital files. It offers a valuable tool for both the creators and users of digital images by describing an image’s technical characteristics, its color profile, content, context, licensing terms, and most importantly, the identity and contact information for the rights holder.
Metadata comes in many forms and schemas, from EXIF, to ICC profiles, IPTC, XMP and PLUS. Metadata needs vary for stock image distributors, magazines, publishers, print and web designers, and photographers maintaining their own libraries. When requesting or delivering digital image files, understand and use metadata to streamline the production workflow. It’s increasingly common for stock-image distributors and magazine publishers to develop custom XMP metadata panels that conform to their particular needs.
Fine Art Reproduction
Creating and preparing digital reproductions of fine artworks requires all the careful attention to details already presented, but it also poses significant additional challenges. Unlike typical photo reproduction, the colors within digital files of artwork are not subject to interpretation or individual preference. The reproduction must produce the same perceived color (within physical limitations) as the original artwork.
UPDIG-DISG Guideline Generator
The UPDIG-DISG generator offers a handy supplement to reading and absorbing the above information. By filling out this web form, you will create a simple, accurate and useful set of digital image submission guidelines. This should be equally useful for developing digital file specifications to fulfill particular needs and for those who need to diplomatically ask for more information than the usual “make it 300 dpi.”
Please try it. This version is a beta, and we will appreciate your feedback.