More about Raw

I've written about Raw images before but as I progress along my learning path, I thought I'd write some more on the subject and explain in a little more detail what actually happens when you take a Raw or a JPEG image.

Raw versus JPEG

Taking photographs in Raw uses significantly more of the camera memory than using JPEG to shoot.

Consider the image below, for example. Taking this shot in Raw uses almost 21MB of data space. The same image in JPEG format, uses just under 1MB.

What makes a Raw file so much larger than a JPEG? 

Shooting in Raw means the camera records information on each individual pixel within the image. The Raw image has a much greater dynamic range (colour variations within an image) than a JPEG. The stored information includes details of hue, saturation, and brightness. This leads to high quality images but a high memory requirement for storage.

A JPEG image meanwhile groups pixels with similar information into what is known as an artefact. The artefact is essentially an overall average of pixels which individually hold similar information. This might be a section of sky, for example, where the colour is very uniform and pixel information is averaged to achieve a single colour. This uses much less memory than a Raw image but also loses much of the information which a Raw image would contain.

As Raw images contain much more information, when processing the picture you will be able to draw out more of the detail and achieve a look much closer to what you actually saw. 

The image above was taken using the JPEG format. You can get an idea of the colours of the sunrise in the photograph but had I shot in Raw instead, I would have been able to bring out many more of the colours which were actually visible. The JPEG picture has combined individual pixels into artefacts which retain the overall warm tones but loses some of the individual colour range.

The image below was taken in Raw format and I have processed it to bring out the colour range. It was an incredible sunrise to witness and a JPEG image might have looked eye-catching but not to the same extent. To give an idea of the extent of the colour in the sky, social media and news channels all carried stories of the sunrise. It really was that impressive and unusual!

As I explained in my previous post, Raw images will not open on every platform but most cameras will come with a processing package which can handle Raw files. Once edited, you can then save them into JPEG format. I would particularly recommend using Raw for landscape photography, and for sunrises and sunsets. The colours to be seen can be stunning and it is a shame to lose these within the photograph. Part of the joy of photography is in sharing the experience with others after the event. Before using Raw images, I would often find myself caveating photographs by commenting that “the colours were much more dramatic in person”. Since starting to use Raw more often, I can present a much closer version of what I actually saw. It makes getting up to catch the dawn much more worthwhile!