From 74de0a0b7a42414a497cfa462bb47002f644112c Mon Sep 17 00:00:00 2001 From: wpferguson Date: Fri, 19 Feb 2021 17:39:34 -0500 Subject: [PATCH] Added contrib/fujifilm_dynamic_range documentation --- .../scripts/contrib/fujifilm_dynamic_range.md | 61 +++++++++++++++++++ 1 file changed, 61 insertions(+) create mode 100644 content/lua.scripts.manual/scripts/contrib/fujifilm_dynamic_range.md diff --git a/content/lua.scripts.manual/scripts/contrib/fujifilm_dynamic_range.md b/content/lua.scripts.manual/scripts/contrib/fujifilm_dynamic_range.md new file mode 100644 index 0000000..b27d9d9 --- /dev/null +++ b/content/lua.scripts.manual/scripts/contrib/fujifilm_dynamic_range.md @@ -0,0 +1,61 @@ +--- +title: fujifilm_dynamic_range +id: fujifilm_dynamic_range +weight: 105 +draft: false +author: "people" +--- + +## Name + +fujifilm_dynamic_range.lua - + +## Description + +Support for adjusting darktable exposure by Fujifilm raw exposure +bias. This corrects for a DR100/DR200/DR400 "dynamic range" setting. + +Based upon fujifilm_ratings by Ben Mendis + +The relevant tag is RawExposureBias \(0x9650\). This appears to +represent the shift in EV for the chosen DR setting \(whether manual or +automatic\). Note that even at 100DR \("standard"\) there is an EV shift: + +100 DR -> -0.72 EV +200 DR -> -1.72 EV +400 DR -> -2.72 EV + +The ideal would be to use exiv2 to read this tag, as this is the same +code which darktable import uses. Unfortunately, exiv2 as of v0.27.3 +can't read this tag. As it is encoded as a 4-byte ratio of two signed +shorts -- a novel data type -- it will require some attention to fix +this. + +There is an exiv2-readable DevelopmentDynamicRange tag which maps to +RawExposureBias as above. DevelopmentDynamicRange is only present +when tag DynamicRangeSetting \(0x1402\) is Manual/Raw \(0x0001\). When it +is Auto \(0x0000\), the equivalent data is tag AutoDynamicRange +\(0x140b\). But exiv2 currently can't read that tag either. + +Hence for now this code uses exiftool to read RawExposureBias, as a +more general solution. As exiftool is approx. 10x slower than exiv2 +\(Perl vs. C++\), this may slow large imports. + +These tags have been checked on a Fujifilm X100S and X100V. Other +cameras may behave in other ways. + +## Usage + +Start this script from script manager + +## Additional Software Required + +exiftool (https://www.sno.phy.queensu.ca/~phil/exiftool/) + +## Limitations + +## Author + +Dan Torop + +## Change Log