Shooting in RAW
- — 22 November, 2005 11:56
If your camera has a RAW capture mode, and you've been wanting to try it out, now is a good time.
A year ago, if you had asked me what format was best to shoot in, I would have said--without hesitation--to use JPEG. It's not that I love JPEG's tendency to compress your files, and therefore compromise image quality. It was that JPEG was the best way to quickly and efficiently capture and edit digital photos.
That's still mostly true. But while RAW was once an arcane and difficult format to work with, these days RAW support is built into all the major image editing suites. So if your camera has a RAW capture mode, and you've been interested in trying it out, now is a good time.
What's RAW? And Why Use It?
Believe it or not, RAW is not really a single file format at all.
Every camera manufacturer has its own native file format; collectively, all these formats are referred to as RAW. Canon RAW files use the .crw and .cr2 extensions, for instance, while Nikon cameras create .nef files. They are all unique and proprietary; the files in these various formats are incompatible.
But no matter what flavor of RAW you use, the idea is the same. RAW files are uncompressed, pristine representations of what the camera's image sensor captures when you press the shutter release. RAW images are totally unprocessed. With JPEG photos the camera performs a host of tasks such as white balance adjustment, colour correction, and image sharpening. Perhaps most importantly, RAW files preserve all of the colours originally captured by the camera--usually 12 bits per pixel. When a picture is saved as a JPEG, the camera reduces the total number of colours to just 8 bits per pixel. RAW's higher colour fidelity adds up to better photos, especially if you edit your images.
So how do the two formats compare in real life?
Here's a detail from a photo I took with a Nikon D100 camera in JPEG set to the highest quality. The same subject, captured in RAW, looks slightly less noisy due to the lack of JPEG colour fringing; but otherwise, it's pretty much the same. As a point of comparison, I ran the JPEG version through Noise Ninja ($35), a noise reduction filter. The result is better than the RAW image.
Of course, this is just one example, and it fails to illustrate the benefits of editing with higher colour fidelity. I just wanted to demonstrate that there's nothing magical about shooting in RAW.
The Downsides to RAW
There are some disadvantages to working in RAW.
First and foremost is the time it takes to save each image on your camera. Most modern cameras can save even large JPEG images more or less as fast as you can shoot them. But RAW images are another story. On my 6-megapixel Nikon, for instance, each RAW image takes about 40 seconds to get saved to the memory card. That adds up to 2.5 minutes to empty my camera's four-picture buffer, which is the equivalent of 14 eternities in picture-taking time.
File size is another consideration. My top-quality JPEG images clock in around 2.5MB each, but their RAW counterparts are a somewhat heftier 4.5MB. That's not as big a deal as it used to be, since you can now buy a 1GB memory card for less than US$100. But if you have a smaller memory card, it's worth considering.
Fortunately, while RAW can make everything else slightly more complicated, there's nothing particularly unusual about moving RAW files from the camera to the PC. Use whatever technique you prefer--a camera connection cable, memory card reader, even wireless, if your camera offers such a feature. After the pictures show up on your computer, though, RAW is a different story.
In the past, since most image editors didn't understand the RAW format, it was also a pain in the neck to view, edit, and organize your RAW photos as well.
Thankfully, that's changed. All of my favourite image editors now work with RAW images just as if they were JPEGs. No matter whether you use Adobe Photoshop Elements, Microsoft Digital Image Suite, Corel Paint Shop Pro, or Ulead PhotoImpact--the most popular commercial photo editors--you'll get RAW support if you upgrade to the newest version.
However, Microsoft Windows XP doesn't know anything about RAW files. In your folders, RAW images appear with nondescript icons instead of thumbnail previews of the photos they contain. And don't bother double-clicking on a RAW file; it won't open the Picture and Fax Viewer to display the image.
But there's a solution: Microsoft's free RAW Image Thumbnailer and Viewer. This PowerToy lets you preview, see thumbnails, and print RAW images as if they were any other file format that Windows understands. It also gives you the ability to see RAW images on the desktop without special RAW image management software.
Depending upon what image editor you use to edit RAW files, your experience will vary. Most programs allow you to make some initial adjustments to your RAW photo before loading it onto the editing canvas. Paint Shop Pro, for instance, offers a simple window in which you can adjust the white balance, exposure compensation, and sharpening; Photoshop Elements delivers a powerful and elegant interface that lets you fiddle with the image's histogram before loading it into the editor.
So, now you're wondering if you should take the plunge. If you already have an image editor and a camera with RAW capabilities, why not? Give it a spin and see if you like it.
If you'd have to spend money to experiment with RAW, though, tread carefully. The JPEG format, used with low compression, is an excellent tool and gives results that are surprisingly similar to RAW. Indeed, you won't see a dramatic difference in the quality of your photos by switching.
RAW's real benefit comes in by making it easier to get high-quality results when you edit your photos on the PC. If you rarely spend much time editing your photos, using RAW may still be more trouble than it's worth.