Bit depth sets how many distinct brightness levels each colour channel can record. An 8-bit channel has 256 possible values; a 16-bit channel has 65,536. Combined across red, green, and blue, an 8-bit image can represent about 16.7 million colours total \u2014 plenty for a finished, unedited photo, but a much shallower well to draw from once significant colour correction is applied.<\/p>
The practical consequence for archiving shows up in gradients: push the shadows or highlights of an 8-bit sky enough and the limited number of intermediate values can produce visible banding, because there simply aren’t enough distinct tones to smooth the transition. A 16-bit master has far more values to redistribute during editing, which is why RAW and 16-bit TIFF are the preferred master formats for assets expected to undergo significant post-processing, with 8-bit reserved for finished delivery derivatives where file size matters more than editing headroom.<\/p>","protected":false},"excerpt":{"rendered":"
The number of bits used to record each colour channel’s tonal value per pixel, most commonly 8-bit (256 levels per channel) or 16-bit (65,536 levels per channel).<\/p>\n","protected":false},"author":0,"featured_media":0,"template":"","meta":{"footnotes":"","faq":[{"question":"What is bit depth?","answer":"The number of bits used to record each colour channel's tonal value per pixel, most commonly 8-bit (256 levels per channel) or 16-bit (65,536 levels per channel)."},{"question":"Why do DAM archival masters often use 16-bit rather than 8-bit?","answer":"Heavy colour correction on an 8-bit file can cause visible banding in gradients like skies, while a 16-bit file has enough intermediate tonal values to absorb the same edit smoothly."},{"question":"How many total colours can an 8-bit RGB image represent?","answer":"About 16.7 million (256 x 256 x 256 combined across red, green, and blue) \u2014 plenty for a finished, unedited photo, but a much shallower well once significant colour correction is applied."},{"question":"What's the risk of archiving only the flattened 8-bit derivative?","answer":"It discards the tonal headroom of the original 16-bit RAW or TIFF, losing what's needed for future heavy retouching or colour grading, since those intermediate values can't be recovered by later re-editing."},{"question":"Why does banding appear in gradients?","answer":"Pushing the shadows or highlights of an 8-bit sky enough exhausts the limited number of intermediate values, so there aren't enough distinct tones left to smooth the transition."},{"question":"Which bit depth should a DAM's master-retention policy protect?","answer":"The highest bit depth version available, RAW or 16-bit TIFF, reserving 8-bit for finished delivery derivatives where file size matters more than editing headroom."}],"checked_date":"2026-08-07","sources":[{"statement":"An 8-bit-per-channel image supports 256 tonal values per channel; a 16-bit-per-channel image supports 65,536.","source_name":"Photography Life","url":"https:\/\/photographylife.com\/8-bit-vs-16-bit-images","checked":"2026-08-07"}],"kicker":"","fact_checker":0,"reading_time":0,"revisions":[],"seo_title":"","seo_description":"","noindex":false,"related":[2483,2444,2490,2557,2509,2494],"definition":"The number of bits used to record each colour channel's tonal value per pixel, most commonly 8-bit (256 levels per channel) or 16-bit (65,536 levels per channel).","why":"Archival masters in a DAM are often stored at 16-bit rather than 8-bit because heavy colour correction on an 8-bit file can cause visible banding in gradients like skies, while a 16-bit file has enough intermediate tonal values to absorb the same edit smoothly. Once a file has been flattened and saved at 8-bit, the discarded intermediate values can't be recovered by later re-editing, so a DAM's master-retention policy should protect the highest bit depth version available, not just the finished delivery file.","example_rows":[{"field":"8-bit per channel","values":"256 tonal values per channel \u2014 typical for web\/delivery JPEGs"},{"field":"16-bit per channel","values":"65,536 tonal values per channel \u2014 typical for RAW\/TIFF masters"},{"field":"8-bit RGB total","values":"~16.7 million total colours (256 x 256 x 256) \u2014 standard finished image"}],"mistake":"Archiving only the flattened 8-bit JPEG derivative as the permanent master and discarding the 16-bit RAW or TIFF, losing the tonal headroom needed for future heavy retouching or colour grading.","deep_link":""},"silo":[24],"class_list":["post-2487","glossary","type-glossary","status-publish","hentry","silo-glossary"],"_links":{"self":[{"href":"https:\/\/picajet.com\/articles\/wp-json\/wp\/v2\/glossary\/2487","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/picajet.com\/articles\/wp-json\/wp\/v2\/glossary"}],"about":[{"href":"https:\/\/picajet.com\/articles\/wp-json\/wp\/v2\/types\/glossary"}],"version-history":[{"count":3,"href":"https:\/\/picajet.com\/articles\/wp-json\/wp\/v2\/glossary\/2487\/revisions"}],"predecessor-version":[{"id":3487,"href":"https:\/\/picajet.com\/articles\/wp-json\/wp\/v2\/glossary\/2487\/revisions\/3487"}],"wp:attachment":[{"href":"https:\/\/picajet.com\/articles\/wp-json\/wp\/v2\/media?parent=2487"}],"wp:term":[{"taxonomy":"silo","embeddable":true,"href":"https:\/\/picajet.com\/articles\/wp-json\/wp\/v2\/silo?post=2487"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}