Users of DSLR cameras, bridge cameras and indeed some advanced compact digital cameras will be aware of the option to record their digital images in either JPEG or raw formats (some DSLRs also offer the option of TIF, but that won’t be discussed here). It’s true that the subject of whether to shoot in JPEG or raw format rears it’s head on every photography forum at one time or another, and it’s very interesting to see the reasons given for using a chosen format. Of course the real answer is that there is no finite answer – it really depends on many factors, circumstances and requirements, and even just personal preference. This post will look at the pros and cons for both JPEG and raw format shooting, and explain possible situations which may favour one or the other. Firstly, here’s an overview of each of the formats…
What is a JPEG file?
Most people know that a JPEG is a compressed digital image or photo file format. Most people also know that the obvious advantage to using JPEG format is that it uses less space on your memory card, your hard drive and is easier to send via email or upload to web thanks to it’s smaller, compressed file size. JPEG is an acronym for Joint Photographic Experts Group, and it is a lossy form of compression which means that it discards or loses data in order to reduce the file size. A JPEG file from a digital camera will have had some form of image processing applied by the cameras processing ‘engine’, the parameters of which are usually custom-configurable to varying degrees depending on the camera. It is usual that cameras will offer varying degrees of compression of the JPEG files it records, from ‘fine’ to ‘basic’ with the latter having the largest compression and therefore degradation, for the purpose of this article we will assume JPEGs at their highest quality.
What is a Raw File?
A raw file is an image file (captured by a digital camera in this instance) captured as the image sensor ‘sees’ it. They are so-called because the file requires digital processing before printing or viewing to it’s full potential, therefore it is ‘raw’. Raw files are sometimes referred to as ‘digital negatives’ because of their similarity to negatives in film photography. It’s worth noting that many cameras offer the option to record raw images as uncompressed, lossless compressed and lossy compressed, though this article assumes uncompressed raw files – the highest quality and largest file size. Each camera manufacturer uses it’s own file extension for raw files, for example Canon use CR2 and Nikon use NEF).
So in summary they are both digital image formats, JPEG discards data and offers a smaller file size and (uncompressed) raw does not discard any data therefore the file sizes are considerably larger. For example a full frame Nikon D700 produces raw files of around 20-25MB, and large, ‘fine’ JPEGs that are 3-4MB. As you can see there’s a significant difference in file size, so when should you use JPEG and when should you use raw? Ultimately you use what suits you, your shooting style and your situation but here are some notes that may help you to decide.
When JPEG is Best
As mentioned JPEG does discard data in order to greatly reduce the file size, but for many circumstances and applications it will not make any difference at all to the viewing of the images – especially when the camera records to the highest quality option available. This is a general guide so consider all factors before deciding, but you should consider recording in JPEG if:
- You will only view your images on a computer screen
- You shoot hundreds or thousands of frames per day/trip
- You will only print smaller, standard size photos (6×4, 7×5)
- You have limited card space available
- You do not have access to a PC, laptop or workstation with raw editing software (most cameras come with a disc featuring such software)
- You need to publish images quickly, i.e. event, news and sports photographers often shoot exclusively in JPEG to expedite the process of getting images to print or website
- You do not intend to heavily post-process your photography, data and therefore dynamic range is lost in JPEG format which limits what can be achieved
When Raw is Best
As touched upon previously, raw files contain more data and therefore more dynamic range, enabling more in-depth post-processing without blowing highlights or losing detail in shadows – indeed, they have to be processed to achieve their full potential. Again, this is a general list of reasons, but you should at least consider recording in raw if:
- You are an enthusiastic post-processor
- You intend to use your images commercially
- You intend to present a single image in various styles
- You require the ‘safety net’ of maximum dynamic range
- You must have the largest, highest quality images
So there you have it, set your format and go shoot!