Once I have images uploaded and indexed by Shotwell (previous post) it’s time to start editing using Darktable, I should perhaps mention that Darktable can also be used to index a whole library of images but I prefer the Shotwell/Darktable method. The software looks similar to Adobe Lightroom, perhaps not quite as powerful but for an amateur or advanced amateur it has all the tools necessary and it is of course free! The software supports RAW, JPEG, PNG, TIFF, PFM and EXR formats, and as mentioned previously is non-destructive, (changes are only applied when an image is exported). Darktable is primarily an image editing tool but also has some simple manipulation tools such as spot removal. Help can be found in several places, the Darktable home page can be found here, the on-line manual can also be accessed via the home page, a PDF manual can be downloaded from here, and I should add that though there is no “official” forum, help can be found on this Google+ site. At present this software is not in the normal Ubuntu repository but can easily be downloaded and installed from a trusted repository, see the Darktable homepage for more info, the installation is very simple if you choose to use Ubuntu (similar to a Windows install) and to add the repository so that updates are downloaded is also very simple. I will be showing a simple import and edit workflow in this post, the software has far too many “bells and whistles” for me to go into too much detail but I will point out what I find useful and mention some of the plugins available.
The GUI is perhaps a little quirky the first time you open it, so I will include a few screenshots to show the way, when opened you will notice in the top right-hand corner that the GUI shows three main headings, Lighttable – Darkroom -Tethering, images are imported from the Lighttable mode, editing takes place in the Darkroom and Tethering allows the direct control of supported cameras via USB, a list of supported cameras can be found here, I have tested this function with my Canon EOS 600D and it worked fine but I will not be going into any further details concerning tethering at present (perhaps in a future posting).
Import can be done in several different ways, as mentioned previously I will normally use the “Open image in external editor” from Shotwell, but it is of course just as easy to do by clicking on Import image (import image/images) Folder (import folder images as film roll) or Scan for devices which will check to see if any device (example: USB connection to camera) is connected and has files for transfer.
Clicking on an imported image thumbnail will open it in Darkroom mode, as seen below, on the left panel (top left) Snapshots (takes a snapshot and splits display so that you can compare changes made, left: snapshot – right: active), History shows what has been applied to an image, clicking on a particular line will show changes made to that point, clicking on 0 (Original) returns you to the unedited start image. Next is the Colour Picker, this is quite advanced, allows you to store picked colours, Image information shows short form EXIF information, note! Darktable does not strip EXIF from edited images.
Right panel (top right) shows a histogram for the image being edited (changes can be made directly in the histogram by dragging) under this there is a row of icons, these are for the different groups of plugins (Basic, Tone, Colour, Correction, Effect), now we come to the interesting part, the panel under the icons is configurable, you choose the plugins (more about this later) you wish to have on the panel, this takes up less real estate and if you work with a fairly standard set-up helps keep the interface uncluttered. In the image shown below I am using the Velvia plugin (useful for landscapes, don’t always use it), Sharpen (default level), Crop and rotate (including Keystone for tilting image correction) and finally on this view Exposure, a lot of these plugins are configurable (using sliders), any settings made can be stored as pre-sets.
At the bottom right of the above screenshot you will see More plugins, clicking on this will show all available plugins (image below) these are too numerous to list here, there is a full list in the manuals also the Wikipedia Wiki for Darktable found here gives more information, More plugins also shows if a plugin is active and chosen as a favourite. Although not shown on the Darkroom mode image above there are of course the standard Levels and Curves plugins, also one that has been added fairly recently called Shadows and Highlights which even at default settings can do wonders to a seemingly flat image.
Finally I should perhaps mention B&W conversion, Darktable has several tools for this depending upon the kind of result you require, I normally use the Monochrome plugin, but you could also use the Colour correction, Colour zones or Channel mixer plugins, when activated the Monochrome plugin (image below) is shown, the ring in the middle can be enlarged and moved to the difference colour areas to enhance specific parts of the image, similar to using colour filters on the camera.
So using Shotwell and Darktable together I have a seamless workflow which will normally only take a couple of minutes to adjust/correct an image, after adjustment the image is exported to a folder named Darktable_modified on my hard disk, but there is also support for exporting to Flickr, Picasa, sending as mail, it will even produce a simple website gallery for you! OK Darktable has a bit of a learning curve (but no worse than other programs of this calibre that I have tried) and for free software I am certainly not complaining! I can use it for more than 90% of my images and find myself returning to it even though I have other similar programs on my PC, the next post will show the software used (Corel Aftershot Pro) when Darktable doesn’t quite cut it.