Getting more nuanced with compositing

In this week's edits I look at some trickier blends while compositing with the watermark module. I use a 15 second and a 1/4 second exposure of the supermoon rising and create an HDR image with parametric blending. I discuss some considerations involved in this composite in an attempt to show more nuance associated with the process.

The Edit My RAW this week is a shot from Thailand that was previously processed with beautiful results. I attempt to compliment the photographer's work with a few of my own touches.

The RAW files used in this video are available here
Supermoon (15 second)
Supermoon (1/4 second)
Thank you for the contribution Norman 🙂

Here is my latest version of my compositing script:


ls -t .config/darktable/watermarks/tmp* |grep -v svg |head -n1 |read file
inkscape -f "$file" -l '.config/darktable/watermarks/tmp.svg'
ls -l '.config/darktable/watermarks/tmp.svg' |cut -d' ' -f5 |read size_n
ls -lh '.config/darktable/watermarks/tmp.svg' |cut -d' ' -f5 |read size_h
[ $size_n -gt 8000000 ] && echo "File too large. Size $size_h, but needs to be smaller than 8M." || echo "File size okay $size_h"

I set it up with a hotkey sequence and use it often now.

Parametric Masks

Parametric Masks

In this video I demonstrate the functioning of the parametric mask sliders in Darktable, use my new compositing functionality on a contributed RAW file, and introduce my Lab color reference chart.
Along the way, there are quick tips on Inkscape and on adjusting panel width and font size in Darktable. I use compositing in Darktable like an old hand now, but here's a quick reminder from last week: Keep your SVG file under 8mb; use Inkscape to convert it from a bitmap like this:

inkscape -f filename.jpg -l filename.svg

and put your SVG file here


The RAW file used in this video is available here. Thank you Jack for the contribution 🙂

Compositing with Darktable

Extend Darktable’s functionality by compositing with the watermark module

In this video tutorial I look at compositing with the watermark module. The procedure is simple but powerful. Here's how it works:

Darktable's watermark module allows you to overlay an svg file on the current canvas. I find 8mb to be the current upper limit on the file size of the svg in order for Darktable to import it properly. A bitmap image can be converted into an svg file by using inkscape like this:

inkscape -f filename.jpg -l filename.svg

It's that simple. The svg file needs to be located in


Blending can be accomplished with the usual suite of blending operators (drawn and parametric).

* note: in this video I use the Raw black/white point module... but that is probably not a good idea. The exposure module is the much preferred solution!

The RAW file used in this video is available here. Thank you fatdunky for the contribution 🙂