{"id":1103,"date":"2024-05-27T09:16:48","date_gmt":"2024-05-27T09:16:48","guid":{"rendered":"https:\/\/lasala1.com\/en\/?page_id=1103"},"modified":"2025-01-27T12:48:13","modified_gmt":"2025-01-27T12:48:13","slug":"extended-dynamic-range-film-scanning","status":"publish","type":"page","link":"https:\/\/lasala1.com\/en\/extended-dynamic-range-film-scanning\/","title":{"rendered":"Extended Dynamic Range Film Scanning"},"content":{"rendered":"\n

Preserving the full dynamic range of motion picture film with exposure bracketing digitization<\/h1>\n\n\n\n

Setting the proper exposure values for every film digitation it’s not always an easy task. Multiple criteria coexist at this phase, analog and digital, and a wide range of technical aspects to evaluate may arise in addition to the film image itself. It is advisable not to forget that decisions made at this stage are not trivial. Exposure settings play a particularly critical role in the film digitization process, since this step will limit all subsequent restoration and preservation results that follow.<\/p>\n\n\n\n

The challenge of digitally retaining the full density of negative film or the higher density of print film may not be a straightforward target if incorrect exposure settings are set in the film scanner. Additionally, cancelling and restarting scanning sessions as the film advances when such exposure errors \u200b\u200bare detected may not always be an option either, especially when timings are very tight or the film is in fragile state and we are instructed to prevent film damaging. Then, what exposure values do we choose? Conservative ones to ensure shadow detail at the risk of clipping highlights? How to estimate highlight clipping if we can\u2019t move to some brighter film scenes as desired?<\/p>\n\n\n\n

Extended Dynamic Range Film Scanning<\/strong> can assist here. Let’s see in context what having up to 5 different exposure values \u200b\u200bper frame provides.<\/p>\n\n\n\n\n

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Dark scene as exposure reference<\/figcaption><\/figure>\n\n\n\n
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Clipped scene due exposure reference<\/figcaption><\/figure>\n\n\n\n
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Recovered with Extended Dynamic Range<\/figcaption><\/figure>\n<\/figure>\n\n\n
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\nClick images to enlarge.\n<\/div>\n<\/figcaption>\n\n\n


The dark scene was used as a reference to calculate the exposure values \u200b\u200bfor the film digitation (left image). Criteria for protecting shadow areas dictated these adjustments, and as a result, the bright scene that follows may quickly suffer from highlight clipping<\/strong> (middle image). Thanks to the Extended Dynamic Range Film Scanning mode<\/strong>, the brighter scene can be easily recovered using some of the digital versions that includes more appropriate exposure values (image on the right). In this example, after reviewing 5 exposure versions<\/strong> generated by the scanner, the one with -1 EV<\/strong>, was what best fitted the project’s primary color correction without suffering from highlights clipping.
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