Question: My new camera has a setting to shoot in monochrome. Is it better to use this in-camera setting or convert to monochrome while post-processing?
Answer: Most cameras (with the exception of entry-level compacts, action cams and most smartphones) offer both JPEG and RAW functionality. In the majority of shooting situations, you probably won’t notice a huge amount of difference between the two, except that RAW files are much larger so write slower and fill up memory cards faster. This doesn’t mean RAWs have a higher resolution, but they do hold more image information, containing all of the ‘raw’ data from the sensor. JPEGs, on the other hand, are quite heavily compressed, so some of the information the sensor collects is simply discarded. In this way you might think of a RAW file as the equivalent of a negative, and a JPEG as the equivalent of a print.
So what information is actually lost during in-camera JPEG conversion? Well, most importantly JPEGs have a smaller dynamic range, so less image data is recorded in shadow and highlight areas. This means if you mis-expose an image at the time of shooting, you may struggle to correct it afterwards. In addition, JPEGs are converted to 8-bit from 12-bit or 14-bit, meaning significantly fewer shades of colour, which can be important when shooting blue skies or other large areas of similar colour. Other symptoms of JPEG compression can include a lack of control over white balance, ugly compression artefacts, oversharpening in-camera, and poor demosaic algorithms that reduce image sharpness.
Quality v Convenience
But while RAW is clearly a better quality format, JPEGs aren’t without their advantages. Their tiny file size allows faster burst shooting and takes up less storage space, and they offer a universal file type. JPEGs can be shared, edited or displayed anywhere without the compatibility issues of RAW. If you don’t process your shots on a computer, you might even prefer the look of JPEGs, which usually look a little punchier straight out of the camera owing to in-camera processing. RAWs offer top quality, but there are times when shooting JPEGs is more convenient.