In my post about whether to buy a DSLR or not I noted that one of the plus points was that it could shoot RAW. But what is it? What difference does it make to my photos? Should I use it? There is a lot of opinion out there on this issue so I went back to the facts to make my own mind up.
What is RAW?
RAW is a file format that your camera can use to save your photos, you have probably hear of JPEG which is probably the other format your camera can use. JPEG files have the extension .jpg but, confusingly, RAW files have different extensions set by your camera’s manufacturer. My Olympus creates .orf, Nikons .NEF and Canons .cr2. So how is a RAW file different from a JPEG? The RAW file is just that, raw data straight from the camera’s sensor where as a JPEG file has had all of the camera’s settings applied to it to process the image into a use-able format. The JPEG image has also been compressed to a smaller size by discarding some of the RAW data it no longer needs now the settings have been applied. The flow chart below is probably the easiest way to describe it.
So the RAW file is just a file containing the data straight from the cameras sensor and a JPEG has had all of the settings selected by the camera applied. What settings? Well things that decide how the final image will look such as contrast, saturation, sharpness, colour balance etc.
So what is the difference between shooting in RAW and JPEG?
There are lots of differences between the two formats and what you can do with the files when you have them, here is my take on just a few of them.
- File size – RAW files are much larger than JPEG files, about 4 times in fact. My 1o mp camera produces 10MB RAW files and 2.5MB JPEG files. That means I need four times as much memory on my camera’s memory cards and computers hard drive but memory is relatively cheap these days, a 2GB card can hold around 200 RAW files which is a lot.
- Continuous shooting speed – As RAW files are larger that JPEGs they take longer to record to your camera’s memory card, this either reduces the speed at which you can fire of a load of shots or reduces the number of shots you can take a the camera’s max speed. This may be an issue if you are shooting sports or wildlife but for most situations it wont be a problem.
- Editability – As RAW files contain all of the information from the camera’s sensor there is a lot more information available to make editing changes with out degrading the image as you would with a JPEG where all of the edits have already been applied once by the camera at the time of shooting. (For all the techies out there RAW files are either 14 bit or 12 bit, JPEGs are only 8 bit). These setting can be applied on the computer using RAW converter software and different settings can be used based on each shot rather than the average settings applied by the camera.
- Compression – RAW files are not compress like JPEGs. The compression stage in creating a JPEG can degrade the image. If all you ever do is print at 6×4 or post low res images on line you may not notice but you will if you print large.
- Need for post processing – RAW files are not really image files, they are just the data from the camera’s sensor so they need to be processed into images before they can be used for anything such as printing or posting online. When shooting RAW this is just done in your computer rather than in the camera. It takes some time to do but you get to control the process in more detail. RAW files can be processed as a batch in you computer as well, creating JPEGs with the default settings but missing out the bit where you get to control the settings.
- Control Over Exposure – As a RAW file is just the RAW data from the camera you can do what you want with that data. One of those things is changing the exposure (brightness) of the photo after you have taken it. This is very useful in tricky light or just to rescue that shot that went wrong.
Which one should I pick?
Well that is entirely up to you and hopefully some of the info above has helped you understand how to make that choice, basically its a trade off between image quality and the ability to edit or rescue a photo after you have taken it versus the pain of large files, the slower shooting speeds and the time you need to take on the computer after shooting to “develop” the images.
I choose to shoot in RAW. Why? I don’t want to loose image quality, even though at 6×4 or online there isn’t any difference every so often I get a shot I want to print large and with RAW I don’t risk not being able to. I like to edit my images and it gives me less to worry about when shooting, instead of worrying about white balance I can concentrate on Aperture, Shutter Speed and ISO and the composition of the shot. Shooting speed isn’t important with the type of images I shoot and I’ve got more than enough memory to save them all.
You may decide to do something different given the requirements of your photography and by all means choose to shoot JPEG if that is best, just do it in the knowledge that it is a trade off rather than that you don’t understand RAW yet.
If I didn’t shoot RAW then this shot would just not have been possible, the left is the developed RAW file, the right the JPEG with default settings. The difference is quite apparent.