Welcome to the very final follow up post for the Camera Challenges from this year. I have promised a couple of times that we would talk about RAW format and today is finally the day!
Most DSLRs should have an option to shoot in RAW, and many bridge and even compact cameras now have this option. A RAW file is effectively like a digital negative (if you can remember those from back in the dark ages of film cameras) and retains all the information recorded on the sensor. In contrast, even the highest quality JPEGs discard around 75% of the information recorded as the camera interprets and processes the image. This is the approximate amount retained across the different quality levels:
Because JPEG is a ‘lossy’ file format, every time you manipulate the file and save it it loses more pixels and more quality. Since the RAW file starts with a lot more pixels, you’re already going to be starting from a better place when you start playing around with things.
Now something that I hear frequently is ‘my camera didn’t get this colour right’. Well the camera does the best it can with what’s available, and you must have noticed that things appear to be a different colour in different lights just by looking at them. Whilst you can try and help the camera by white balancing it to a particular light source, that’s not terribly helpful if you’re moving around with your camera and the light is constantly changing, so most people (myself included), leave the camera on auto and hope! With RAW images, the RAW processor allows you to set your white balance as well as many other settings similar to the way your camera would process a JPEG. That’s not to say you can’t fix white balance and other things after the fact in a JPEG image, but going back to the whole ‘lossy’ issue, it will reduce the file quality with manipulation.
Jack and Edwood did a little modelling for me so that I could show you the difference between images shot in both RAW and JPEG formats. In my camera I can choose to shoot both RAW and JPEG simultaneously, so we know that these images should be identical.
This shot of Jack shows the RAW image straight out of camera with no processing. As you can see the light is very blue, and he’s a wee bit fuzzier round the edges than usual:
This picture shows the difference between the JPEG on the left and the RAW image straight out of camera with no processing on the right. As you can see, when the camera processed the file to produce the JPEG it warmed the light up a bit, but also washed his fur colour out a bit more. The red in his foot and bag is less vibrant, as is his orange scarf, but he is a bit sharper in the JPEG:
This is the RAW processor that you see when you open a RAW file in Photoshop (other photo software is available) It will let you change the white balance both temperature and tint (there is an eyedropper that you can use to sample a white part of the background), you can also increase or decrease the exposure, and change a number of other variables. At this stage I usually only adjust the white balance, and occasionally exposure.
I’m not going to walk you through all the processing steps, but Adobe has a number of books on how to process RAW files. The best book I ever bought on the subject was Scott Kelby’s 7-Point System for CS3. Although we’re now several versions of Photoshop on, the premise is the same, and it’s worth taking a look at, not least for the exercises it includes where you get to manipulate images of his to see the results. If you use the ‘record action’ option, you can basically apply his most common points the same way every time at the click of a button.
Here is the comparison between the JPEG and the RAW after processing. Again the JPEG is on the left. Now the light in the RAW file is warmer, his fur is very much the colour that it is in real life, and he’s sharper than his JPEG alter ego:
Moving onto Edwood, here’s the RAW image straight out of camera with no processing:
Here you can see the difference between the JPEG on top and the RAW image straight out of camera with no processing on the bottom. As you can see, when the camera processed the file to produce the JPEG it kept the background pretty much the same, but made his fur less yellow and his backing fabric more beige:
Here’s the RAW processor image. Interestingly, although it was in exactly the same light, the values recorded for temperature and tint are different from the photo of Jack, the temperature being 4900 rather than 4550, and the tint being 32 rather than 17. You can also see that the graph at the top has a lot more to the left of the peak than the one of Jack:
This is the comparison between the JPEG and the RAW after processing. Again the JPEG is on the top. Post processing, Edwood is actually yellower than he was, and his red necklace is more vibrant. Again, this is much more true to life colour wise than the JPEG version:
So what I’m saying here is that you can process your photos better than your camera can if you shoot in RAW, the question being whether or not you want to put the effort in!