I never used to shoot in RAW. I didn’t see the point. To be honest, it baffled me somewhat and I didn’t fully understand the benefits. I just wanted to take a photo and have an instant image file which I could then email and Tweet around. So I shot in jpeg.
Now, I’m a fully-fledged RAW convert. I look back at my jpeg-shooting era wishing I had RAW files for some of those images.
What’s so great about RAW?
You see, when you take a shot in RAW format, you’re not taking a photograph as such. You’re capturing an unprocessed data file of the scene. Think of it as a negative as per with camera film. That RAW file contains detailed information regarding colours, saturation, exposure, sharpness, white balance and both shadow and highlight detail. The downside is that RAW files aren’t viewable outside of your DSLR without special RAW image viewing software such as PhotoShop or Lightroom.
However, what makes RAW files so useful for photographers is the depth and range of information they hold. An average RAW file may be 25mb in size compared to its processed jpeg counterpart which may come in closer to 8mb. By shooting in jpeg, you’re immediately losing at least two thirds of the image information.
Jpeg Compression and Conversion
This loss of detail comes during the camera’s conversion of the image in to jpeg format. The camera will make preset assumptions regarding image sharpness, noise reduction, white balance and the removal of unrevealed shadow and highlight detail, among other variables. It’ll then compress the remaining data while converting it in to a viewable image. If you then choose to undertake any post-processing, you’re stuck editing a compressed and pre-processed image.
RAW files really come in to their own when it comes to editing and post-processing. With RAW files, you’re adjusting the original data captured by the camera’s sensor – the pixels. This gives you more control, greater accuracy and better results.
RAW vs Jpeg in Practice
One example of this would be as demonstrated below. Here we have an image which has been deliberately underexposed.
We imported the file in to Adobe Lightroom 4 in RAW format and subjected it to shadow enhancement (brightening) and slight image sharpening. We then repeated the editing with a jpeg version of the image.
What follows is a crop and zoom of a section of the two resulting files. On top is the RAW edit. Compare this to the jpeg edit beneath it and immediately you can see how the compressed jpeg struggles to reveal any shadow detail from beneath the pier. What comes through instead is a washed-out haze.
In addition, the RAW file shows an increased sharpness to the grid fencing, better saturation in the wooden beams, clarity to the ‘Yesterdays’ sign and an overall punch. And that’s before we really push the post-processing!
The reason for the jpeg’s failings are simply down to the file no longer containing the information. Using the example of shadow detail, the jpeg will remove any detail it knows won’t be detectable on screen, while the RAW file keeps that information within the image, ready to be revealed. When you brighten the shadows, the jpeg will try and reveal what’s already been removed. Therefore, your editing and post-processing will never produce the results which you’ll achieve from shooting in RAW.
My advice to you…
If you own a DSLR, you’re likely to post-process a lot of your photos – whether it’s a simple crop, a slight sharpen, a tweak to the image’s white balance or a simple black and white conversion. If you regularly perform any of these adjustments, set your camera to shoot in RAW. If you don’t change habit now, you’ll most certainly be making the switch soon.
Author – Oliver Pohlmann