What is the difference between raw and jpeg shooting?
Photography print magazines especially like to create whole articles on this subject – like there is a choice. There really isn’t – unless you’re a press shooter, you’d have to be mad to shoot jpeg if you care about your images. They like to go on and “compare” jpeg and raw images, as if you can actually view a raw file. If you open a raw file, it is converted there and then to fit into the colour space and range of tones that your display device can support. In effect then you are just comparing jpeg to another jpeg – just developed using a different set of values.
OK, before we get into this, lets be clear that file formats are not the issue here – yes jpeg is compressed: well guess what? Nikon cameras can do compressed raw files too (lossless and lossy) and I’ll be surprised if others don’t also. Compression is another debate, and does not really affect the image quality at all. However, as a side effect of making a jpeg, the camera *must* process the image – with no input from you; and that’s what is really at stake here – do you want default processing, or would you like some input to the process?
Having control over the development and processing of our images is not new to digital photography. Before the days of drum scanners and Photoshop, many landscape artists dodged, burned, masked, pre-exposed and selectively treated areas of both the film, and the photographic paper to produce a finished print. Ansel Adams reckoned he did at least 50% of the work on an image in his darkroom. He certainly didn’t send his films off to Bonusprint.
If you shoot JPEG only, the camera processes your image using some pre-sets for white balance, colour treatment, sharpening etc. and produces a finished picture with little or no post capture input from you. This is just what you need if you’re in a hurry. If you are a press photographer for example, where the value of your images diminishes rapidly the second you took the shot. These guys don’t use Photoshop – the images need to go straight from the camera, via WiFi to the laptop and up to the agency ftp server.
If you’re not a press photographer, and have the opportunity to develop the images yourself, rather than accept whatever the camera’s limited processing capabilities can give you, you should capture the raw data and use that instead. For landscape photographers, this is essential. After all, they are creating an image with a target mood, to evoke specific feelings and emotions about the scene – it doesn’t have to be accurate – it’s not a documentary. If you see a landscape photographer using a grey card – they’ve missed the point.
Shooting JPEG only is a bit like shooting Polaroid film albeit a high quality version. The original raw data captured by the sensor is discarded after the JPEG is made. This includes more data than any screen or printer can display: Most good DSLR’s today can capture 1.5 to 2 stops more data either side of the range your monitor or printer can display. It is primarily this extra data that we can exploit by capturing the raw data from the sensor. Using developing software such as Photoshop, PhotoEngine or Lightroom we can choose – wholesale or selectively to bring data originally outside of the visible window, into it.
You cannot view a raw file – you may be able to open the file in Irfanview or other image viewers, however they must effectively create the equivalent of the in-camera jpeg, squashing the data into a colour space, applying a white balance and discard anything that doesn’t fit and then show you that. Open a raw file in your chosen image development software (Lightroom, Adobe Camera raw, Aperture etc) and look at the histogram. Now realise that the histogram continues off the ends. If you add “fill light” or “recover highlights” the extra information is dragged back inside the visible slice on the histogram. Now, if you do this for the entire image, everything else has to “budge up” to make room so you will lose some detail in the mid-tones by doing this. A better way is to selectively do this to the parts of the image that need adjusting, where there is little mid-tone data: that is, areas where it is too light or too dark. You need to do this on the raw file, in either Camera Raw or Lightroom if you’re an Adobe user. You can do something similar in Photoshop using adjustment layers and masks, however you won’t have access to the extra data as you’re editing a bitmap: a rendering of the visible part of the raw file. In Lightroom, or Adobe Camera Raw, we can just paint the adjustments directly onto the image using either the adjustment brush, or graduated filter tool.
Using these techniques we can pull back information into the highlights and shadows where we want them.
Plus, as software improves over the years, we can go back and get a better image from the same raw data. Don’t throw it away (which is what you do when you opt to have the camera process the images to jpegs). Lightroom 3 has done wonders for some of my earlier low light shots in reducing noise, and Lightroom 4 introduced much better handling of highlights and shadows.
So why do so many articles in print magazines pretend that shooting jpeg is an option? I think it’s to create and perpetuate a view held by novice photographers and sold by camera manufacturers that you can just run around with gay abandon clicking the button and end up with fantastic shots (remember that ad for some expensive compact with Kevin Spacey in it?). The reality is, of course that amazing images require hard work, both behind the camera, and in production. The idea that you can “get it right in camera” and compete with photographers that take time over the post production of their images is a lie. People who spout the “get it right in camera” mantra as if the fact they don’t do any post processing is a badge of honour, almost always, don’t know how to process their images. They never learned Photoshop. I never heard anybody who knows Photoshop, trot out that phrase. If you want to compete, you need a holistic understanding of the tools – not just the capture device.
