Sigma’s own software, Sigma Photo Pro, has been shipped with every camera Sigma has produced since the SD9 over a decade ago. Having introduced features like the X3 Fill Light that took full advantage of the Foveon’s remarkable dynamic range, SPP has evolved slowly and whilst it remains a powerful tool for processing the X3F files produced by the Direct Image Sensor (and until the release of Iridient’s Raw developer, the only option for the high resolution 46MP files captured by the SD1 and Merrill series cameras) it is limited compared to third-party offerings available to other camera users. Richard Kilpatrick takes a look at Iridient’s Raw developer.

Iridient’s application does not provide the catalogue and organisational power of Aperture and Lightroom, rather, it offers a nuts & bolts approach to editing raw files from almost any camera, with incredible control over curves and interpretation of the data alongside the valuable ability to crop, freely rotate and export files at any size in a variety of formats including batch processing.
Iridient Digital’s raw developer has been available since 2004 as a Mac OS X application targeting power users. Rather than limiting the options a user has to present a flattering or ‘corporate’ idea of what a file should look like, it’s possible to have detailed control over noise, colour and sharpening and extract the best detail from an image for the intended output. Version 2 was released in 2013 – impressive staying power for any software package – with support for Sigma’s unique format being actively developed and improved since since 2007.
Version 2’s release made Iridient Raw Developer the first third party application to support the Sigma SD1 and compatibility with subsequent models has been added rapidly, 2.01 adding the DP3 Merrill before the camera had even shipped to most users, and now 2.1 updates support further improvements in Sigma and other camera processing. 2.1 has also included a new system of noise reduction with 3 different approaches and auto level adjustment based on ISO, a new channel mixer Monochrome mode, black point compensation, additional colour management options via LittleCMS and for unsupported cameras, use of Apple’s own raw support.
A clean and simple user interface makes full use of Apple’s provided framework, rather than trying to force a bespoke identity onto the application. This contributes to rapid load and response times, even when generating the filmstrip-style previews used when working with a folder, rather than individual image.
 

 
With windows for operations and information, it’s easy to build a layout that suits your own preferences. The histogram can be resized and will display per channel, overall and RGB information. The process panel – above, showing curves and the options available – is your workflow, and has a fixed, natural ‘development’ process.
 

Zooming in at 100% to view detail in the image is very fast – a much quicker process than Sigma Photo Pro’s two-step method of rendering then zooming. It makes adjusting sharpening and noise reduction considerably easier as well, as adjustments are shown in real time.
 
Iridient’s process is very straightforward – it’s not as free form as Camera Raw or Lightroom might feel, but it offers a logical progression from raw file to output file, and greater control over that processing.
 
We’ll start with the raw file source.
 
Input Panel

 
As you can see, the input panel already allows preset parameters and subtle control over colour temperature, tint and shadow/highlight recovery. Further controls are available behind the buttons at the top:
 
Camera Advanced

 
For detailed control over how the raw file is interpreted, for special effects or subtle corrections, Developer allows control of RGB offset values. These can be saved, along with adjustments from the other panels, as presets to be reused for a particular camera or shoot. This set of adjustments – outside of baseline exposure, white and black levels, appear only to apply to Bayer sensors, but can be used to visually approximate the behaviour of different film types, then be saved as a preset.
 
Input Curves.

Curves can also be applied to the raw file preset, seen here is the default for the Sigma DP2M. Iridient allows complex variations at this stage and during processing.
 
Lens Panel
 
The lens profile correction is quite straightforward. Again, settings can be saved and recalled later; Developer also supports LCP files – lens correction profile – as generated by Adobe’s profiler and available to download through shared libraries via that same application. Adobe’s Lens Profile creator can be obtained at this link – Adobe Lens Profile Creator – Mac and the Lens Profile Downloader (for other users’ profiles as well as Adobe’s own) is here – Adobe Lens Profile Downloader – Mac, Air application.
 
These are both Apple OS X applications, as Iridient do not support Windows systems.
 

 
Monochrome Conversion panel

 
Perhaps of less interest to Sigma users since Sigma themselves have introduced a monochrome mode, nevertheless Developer offers a variety of blending and conversion techniques, as well as the advanced curves control, cropping, instant preview of sharpening that might tempt you into processing your Merrill files this way.
 
Curves Panel

The Curves control – for processing, rather than input – allows the same consistent ability to save presets, and many points. It is possible to achieve dramatic effects without any additional software.
 
Adjustment Panel

 
Output Panel

Rotation, cropping and colour management. Presets can be saved, and batch processing can be performed whilst the application works on other files.
 
Finally, Developer offers absolute control over the output file – size, resolution and format.