GFF's Guide to Saving Pictures for the Web
Please notice that this article series was started in 2002! By Martin Joergensen (supported by Steve Schweitzer)
Final compression and using the right format can be as important as taking good photos and scanning them correctly.
Back then digital cameras were few and far between, and film cameras, macrom lenses and scanning your flies in a flat bed scanner was the order of the day.
Today most people have a digital camera (or even a phone), which can do decent macro shots, and much of what you can read here is very out of date. But the general methods and advice still holds, and the articles should still be worth reading.
Macs and pc's - and other types of machines - are readily mixed in today's computer environments. This means that proprietary file formats are no longer useful, because you want to be able to exchange files with other people using other types of computers. Web formats are excellent exchange formats, but unfortunately not well suited for archival purposes. This list covers the most common file formats and comments on their characteristics.
This format is the native Windows format, but it has no advantages over TIFF apart from support in Windows Paint. It is accurate but compresses poorly and has nothing close to the flexibility of TIFF. Use TIFF for archiving in stead. Useless on the web.
The most common format for logos and graphics on the web. GIF compresses fairly well and has no quality loss with respect to pixels, but will convert all colors to fall within a range of maximum 256 colors - sometimes even less. GIF can be used for photos using certain techniques, but JPEG is easier to handle. Useful on the web.
The most common format for photos on the web. This is an extremely well compressing format, but any compression leads to an unrecoverable loss of quality. Use JPEG only for the finished pictures. Useful on the web.
An alternative format for images on the web. Again an potentially well compressing format, but the compression leads to an unrecoverable loss of quality. It doubles as both GIF (limited indexed colors) and JPG (any number of colors) and adds to that the option of transparency, which is not much use on photos, but very useful in other web graphics. Use PNG only for the finished pictures. Useful on the web.
This is a Mac format, which suffers from some of the same problems as BMP. It is also used exclusively on Macs, which makes it difficult to exchange pictures with friends and coworkers. Useless on the web.
Native Photoshop format is a good format for Photoshop users. It maintains all relevant information for that particular program - layers, masks, filters etc., but cannot be read in many other programs. It works equally well on Mac's and pc's and will keep more than adequate quality in stored pictures. Useless on the web.
The best format for storing originals and transporting files. TIFF is accurate and compresses well without loss of quality. TIFF can store all types of pictures - simple and complex, B/W and color, photos and logos. TIFF is platform independent and works on both Mac's and pc's. Useless on the web.