With the relentless advance of digital camera technology, many pro-level and some mid-range digital cameras allow you to record images as RAW files. But, do you need camera RAW, and what are the advantages and implications if you decide to use it?

What Is the RAW Image Format?

In digital photography, the RAW file plays the role that photographic film plays in film photography. RAW files thus contain the full resolution data as read out from each of the camera’s image sensor pixels.

Like a photographic negative, a RAW digital image may have a wider dynamic range or colour gamut than the eventual final image format, and it preserves most of the information of the captured image. The purpose of RAW image formats is to save, with minimum loss of information, data obtained from the sensor, and the conditions surrounding the capturing of the image (the metadata).

A camera RAW Image file contains minimally processed data from the image sensor of the digital camera and are so named because they are not yet processed and therefore are not ready to be printed or edited with a bitmap graphics editor. Normally, the image is processed by a RAW converter in a wide-gamut internal colour space where precise adjustments can be made before conversion to a ‘positive’ file format such as TIFF or JPEG for storage, printing, or further manipulation.

When you capture an image using your camera’s RAW format it is only ISO speed, shutter speed and aperture that have an effect on the captured pixels. When you open the RAW file using a RAW file editor on your Mac or PC you can control settings for white point, colour metric rendering, noise reduction sharpening and so on.

How Do I Process My RAW Images?

Today there are many programs available to process RAW images but, in my opinion, the two best to consider are Adobe Photoshop Lightroom and Apple Aperture. They are both high quality applications that allow fine adjustment and manipulation of your RAW images. Unlike traditional image editing software Lightroom and Aperture are focused on various workflow steps:

• The Library structure allow you to organize your images – similar to that of iPhoto, Picassa or Adobe Photoshop Elements.
• You can Develop the RAW files non-destructively and save them out as JPEGs or TIFFs.
• There are sophisticated Slideshow tools and export features.
• The Print features allow you to create single or picture packages directly from RAW files.
• The Web features make it easy to automatically create web galleries and upload them.

It is possible to open and do limited adjustments in other applications like iPhoto and Picassa, but you will not be able to control your images the way that will allow for full creativity.

My preferred software is Adobe Photoshop Lightroom, as it combines beautifully with Photoshop (a program that I am very familiar with) and makes converting to the DNG format extremely easy.

Adobe Photoshop Lightroom is an astonishingly versatile and capable program, packed with advanced features and clever details, and a real one-stop-shop for all your photo management and processing needs.

The Benefits Of Shooting in RAW

Nearly all digital cameras can process the image from the sensor into a JPEG file using settings for white balance, colour saturation, contrast, and sharpness that are either selected automatically or entered by the photographer before taking the picture. Cameras that produce RAW files save these settings in the file, but defer the processing. This results in an extra step for the photographer, so RAW is normally only used when additional computer processing is intended. However, RAW has numerous advantages over JPEG such as:

• The contents of RAW files include more information, and are potentially higher quality, than the converted results, in which the rendering parameters are fixed, the colour gamut is clipped, and there may be quantization and compression artifacts.
• Finer control in RAW conversion software allows users to manipulate more parameters (such as lightness, white balance, hue, saturation, etc…) and do so with greater variability. As well, the user can typically see a preview while adjusting these parameters.
• Camera RAW files have 12 or 14 bits of intensity information, not the gamma-compressed 8 bits stored in JPEG files (and typically stored in processed TIFF files); since the data is not yet rendered and clipped to a colour space gamut, more precision may be available in highlights, shadows, and saturated colours.
• Large transformations of the data, such as increasing the exposure of a dramatically under-exposed photo, result in fewer visible artifacts when done from RAW data than when done from already rendered image files. RAW data leave more scope for both corrections and artistic manipulations, without resulting in images with visible flaws such as posterization.
• All the changes made on a RAW image file are non-destructive; that is, only the metadata that controls the rendering is changed to make different output versions, leaving the original data unchanged.

The Drawbacks of Shooting in RAW

• Camera RAW file size are typically 2–6 times larger than JPEG file size. While use of RAW formats avoids the compression artifacts inherent in JPEG, fewer images can fit on a given memory card.
• Because of the lack of widespread adoption of a standard RAW format, more specialized software may be required to open RAW files than for standardized formats like JPEG or TIFF.
• The time taken in the image workflow is an important factor when choosing between RAW and ready-to-use image formats. With modern photo editing software the additional time needed to process RAW images has been greatly reduced but it still requires an extra step in workflow.
• Because each RAW file has a different structure depending on which camera it was taken in, it may not be readable by all image editing programs. The files from newer cameras, for instance, won’t be recognised even in the older versions of advanced programs such as Adobe Photoshop without a software update. For this, however, you can make use of the Digital Negative (DNG) format from Adobe, which is effectively a format designed to future proof RAW files without losing any of the data.

Digital Negative (DNG) Format

The intention of Adobe’s DNG File Format for RAW files, is to establish an open industry standard so that all camera manufactures can work to a common set of specifications which will ultimately benefit the entire industry and especially the end user.

Crucially, DNG has the potential to provide photographers with a format they can use to archive images, safe in the knowledge that they will be able to access these images in the future. This removes the reliance on a proprietary format that may, or may not, be supported in the future.

The success of DNG as an open standard would also make it much easier to transfer and share RAW images in complex workflows and between photographers and agencies.

Conclusion

The main consideration when deciding whether or not to capture images using RAW data, is whether or not you want ultimate control over the image settings such as white balance, brightness and contrast, noise reduction, sharpening and colour rendition and are prepared to take the time to make these decisions.

In my opinion, there is no debate. To get the best quality images and to have the most control over your image, you need to use the RAW Image Format. In the same way that you wouldn’t have binned your negatives once you had them printed, shooting straight to JPEG is like throwing away the most important information and severely restricting your future creativity.

I would definitely recommend giving RAW a go. You won’t regret it!