PHOTOGRAPHY

In the first of a two-part series, Alexander Tolstoy shows how to edit RAW files as he explores open source alternatives to Adobe Lightroom.

OUR EXPERT

Alexander Tolstoy is a long-time enthusiast of image editing using Linux. He hides his secret messages in Russian in underexposed areas of his photographs.

Almost everyone is a photographer these days thanks to smartphones and affordable D-SLR cameras. Taking photos can be fun, but it can become so much more - whatever equipment you might own. From starting out as a novice photographer, you can become an enthusiastic hobbyist as your skills improve. You can even turn pro and make money from something that was once just a means of capturing a moment in time.

Somewhere along the way, you’ll come across the phrase “shooting in RAW”. In this tutorial, the first part of a two-part series, we’ll explain what a RAW file is, how it’s an improvement on the JPEG format, and how you can use open source software to work with RAW files. Part two will cover advanced RAW editing techniques.

What is the RAW format?

When we take a photograph that’s saved as a JPEG, we often don’t realise that the camera’s firmware carries out a lot of enhancement steps automatically: colour balancing, de-noising and so on. In contrast, a RAW file is a minimally processed set of data taken directly from the camera’s image sensor. RAW files contain more colour data and therefore can provide a wider dynamic range and gamut, but they’re usually not yet ready for printing or sharing.

The cornerstone of RAW processing is the assumption that a decent photo-editing program on a powerful PC can do a better job of improving the image than a camera’s basic firmware that’s locked within a limited performance range, dictated by the camera’s hardware. Thus the skill in editing RAW files is to manage the RAW-to-JPEG conversion process manually so that you outperform the camera’s own algorithms.

Modern cameras are excellent at auto-processing an image sensor’s data if the photo is taken under ideal lighting conditions (on a bright day, say). However, we might want to fix several trendy effects created by smartphones that prevent RAW images from being trueto-life, such as the ‘beautifying’ smoothing effect (which removes facial skin details) and over-sharpening (the result of the inaccurate belief that the sharper an image is, the better).

For D-SLR cameras, it’s advisable to capture RAW files when there’s no way to avoid less-than-ideal shooting conditions. In this first part of our tutorial we’ll handle the following problems:

Under-/overexposed images that require manual intervention steps

Low-light images shot at high ISO values, which suffer from noise