Darktable-CLI disable auto exposure

Software darktable
1

I have multiple RAW images at multiple exposures. My final goal is to do HDR merging.

When I process each one alone using Darktable CLI, Darktable enhances the low exposure ones by increasing their exposure and the high exposure one by lowering their exposures.

This fundamentally against the purpose of the HDR merging. How can I disable this exposure enhancement that Darktable does by default. (Using the CLI)

2

Hi and welcome to the forum!

You should pass an XMP file with the raw that is used for processing. You can control that setting with what is in the XMP file.

3

Thank you very much for your fast reply!
Any clue what this xmp file should contain? I tired this one but with no luck:

<?xml version="1.0" encoding="UTF-8"?>
<xmpmeta xmlns:x="adobe:ns:meta/">
 <rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#">
  <rdf:Description
    xmlns:darktable="http://darktable.sf.net/"
    darktable:version="4.6.0"
    darktable:basecurve="false"
    darktable:filmicrgb="false"
    darktable:sigmoid="false">
   <darktable:history>
    <rdf:Seq>
     <rdf:li darktable:operation="demosaic" darktable:enabled="true" darktable:params="amaze"/>
     <rdf:li darktable:operation="whitebalance" darktable:enabled="true"/>
     <rdf:li darktable:operation="exposure" darktable:enabled="true" darktable:params="0 0 0 0"/>
    </rdf:Seq>
   </darktable:history>
  </rdf:Description>
 </rdf:RDF>
</xmpmeta>
4

Open dt in GUI. Do an edit to one image to turn off the auto exposure compensation. Close dt and use that xmp in the dt cli.

4 Likes
5

By the way, 4.6.0 is getting a bit old. The latest version is 5.2.1, so you may want to update.

6

If you achieve this to a high standard I would love to see an example posted here. I found HDR very helpful in the days of JPGs but have not seen any convincing advantage with raw files. I find a single RAW exposure can produce the best result in my hands. I always shoot bracketed shots and would love to be able to do HDR from raw but in my hands the results have always disappointed me.

1 Like