by Guy Lerner
May 15, 2003
Ask any professional digital photographer which file format he prefers to shoot in, and chances are he’ll answer “RAW.” For the uninitiated, he’s not swearing back at you, and it’s not some secret password for the Photographer’s Forum Frat Party either. RAW is simply the highest quality, most flexible file format available to digital photographers today.
The problem with RAW – which, I should first explain, is a file containing the raw, unprocessed data captured by the camera’s imaging sensor, hence the name – is that until recently, photographers were very limited in the software available to them that could properly (and quickly) decode RAW files from their cameras. That’s because RAW is not a “standard” like the popular and ubiquitous JPEG or TIFF file formats, and each camera manufacturer usually implements its own proprietary RAW format.
Put another way, RAW files from, say, a Canon digital SLR are not interchangeable with those from a Nikon or Fuji. Without special software, RAW files can’t be loaded up and opened on a PC, as you would do with any of the standard file formats. Cameras that can save their pictures to RAW files are supplied with specially written software to decode those files. In many cases, this software is very basic, offering only modest tools that don’t take advantage of the RAW file’s true potential (read on to find out more about the real value of RAW files). This has resulted in a spate of third-party vendors offering their own products to read and decode RAW files from different cameras, and many of those, such as Chris Breeze’s BreezeBrowser (http://www.breezesys.com) give the photographer all the tools he needs to fully exploit his RAW collection.
Enter Adobe
Without doubt the benchmark for both PC and Macintosh graphics software is Adobe
Photoshop. You’ll be hard pressed to find a professional photographer who
doesn’t own this incredible product, and it’s installed and used by millions of
design, photography and advertising agencies worldwide.
Until now, however, Photoshop offered no way of opening and manipulating digital camera RAW files. Photographers have had to rely on their camera’s software or third-party products to convert and save their RAW files to a format Photoshop understands, and continue the processing work from there. While many photographers didn’t (and still don’t) see this as a problem (because some third-party software is just that good), others have longed for a way to integrate RAW file support into their Photoshop routines.
With Adobe’s recently released Camera RAW plug-in, they can. Developed in response to the booming popularity of digital cameras with RAW support, the Adobe Camera RAW plug-in enables Photoshop (7.0.1, or Elements 2.0 only) to read RAW files from many different cameras. RAW files can be “opened” like any other file, or selected from Photoshop’s File Browser. Once selected, the plug-in interface is loaded, complete with the RAW file.
From RAW to WOW
At this point I’m going to tinker with the traditional review formula and
instead take you through a demonstration of the Camera RAW plug-in. Any questions
you may have from my description above will hopefully be answered here. If you
want to know more about the technical ins-and-outs of the plug-in, or need a
shopping list of features, head over to
Adobe’s Camera
RAW site. If, on the other hand, you want to get down and dirty with RAW,
and see what the Camera RAW plug-in can do for you, read on.
The first thing you’ll notice about the plug-in is how well it’s been integrated with Photoshop. Seasoned Photoshop users will feel right at home with its layout and selection of tools, and even novices won’t be scared off by the comforting simplicity of its design.
I’ve
chosen a portrait of my son for this demo, not because I want to show him off
but because his was the only set of RAW files I had handy at the time of writing
(it doesn’t hurt to have a cute photo to work with, though). I picked the
thumbnail from Photoshop’s File Browser, and by default the Camera RAW plug-in
zoomed it out to fit the preview screen. This may seem trivial, but I mention it
because the speed with which the file was previewed, even on an old Pentium III
PC, was impressive – far quicker than was ever possible with my camera’s
software (but not any faster than with BreezeBrowser).
Once loaded, the file can be previewed at almost any size, because the plug-in window is resizable, and zoom controls on the left-hand side of the preview window let you get right up close to the action.
You’ll begin to get an idea of the power of RAW files by glancing over at the controls down the right-hand side of the window. From the top down, the plug-in gives you precise control over every aspect of your photograph’s technical appearance, from settings specific to your camera, to white balance (more on this later), exposure, shadow detail, brightness, contrast, saturation, sharpness and more.
Best of all, using RAW you know that these settings can be edited with little, if any, loss in quality. Herein lies the power of RAW files: because they contain the raw information captured by your camera, they have not been subject to any form of processing that, using other file formats, can severely degrade the final quality of the image. They are essentially “digital negatives”.
For example, saving your photos as JPEG files saves space on your memory card and hard drive because JPEGs are highly compressed. While RAW files also use a form of compression, JPEGs use what’s known as “lossy compression” that physically discards information from the photograph to make it smaller. RAW files are compressed using “lossless” compression, so the information stored is identical to the information captured.
The
real value of RAW files, however, is that they allow you, through software such
as the Camera RAW plug-in, to change aspects of the scene that would otherwise be
hard-coded into other file formats. Take white balance for example. White
balance is the measure of the colour temperature in a scene. The temperature
differs considerably from one scene to another, depending on the time of day,
cloud cover, degree of shade and the type of light used (tungsten light produces
a different colour temperature to sunlight, for instance). The white balance
setting you choose affects the way a scene is recorded – and the way the data is
converted – in your camera, and affects how the colours in your photograph are
translated.
When you save to a RAW file, the white balance setting is not taken into account. The file opens up in the plug-in with the setting you selected (I left the camera in Auto white balance mode for this portrait), but you are free to change that setting to anything else you like using the white balance options menu. Select a new white balance setting, and notice how the colours are affected in the preview window. Since I shot the portrait in the shade of tree, changing the white balance setting to “Shade” immediately renders my son’s skin tones and the saturation of his pyjamas more vividly and accurately.
Choosing a preset setting doesn’t always have the desired result, however. Other factors in the scene, such as cloud cover and even exposure can affect the way colours are rendered. Just as is possible with advanced digital cameras, Camera RAW allows you to fine-tune the colour temperature incrementally until you achieve the desired result. Move the Temperature slider to the left to cool down the colours, and to the right to warm them up. It also gives you control over the colour tint, although I’ve never relied on this slider.
Yet
another powerful trick possible only with RAW files is the ability to dial-in
exposure compensation. As a photographer in the field, you sometimes need to
make very quick decisions to nail the exposure you want for a scene, and as any
photographer will tell you, you don’t always hit the nail on the head. If you’re
shooting to RAW, that’s no longer a problem. As long as you’re within reasonable
reach of the exposure you want, Camera RAW allows you to increase or decrease
the exposure of your picture in small increments, pulling out details from
underexposed shadows and toning down overexposed highlights (highlights are far
more difficult to recover than shadows, incidentally).
This doesn’t mean that you no longer have to pay attention to your exposure technique, but it does give you a safety net when you’re off by a few f/stop fractions either way. Any more than that and even Camera RAW (or any other RAW conversion software, for that matter) won’t be able to do much for you, and you’ll have to resort to the powerful (and complex) image manipulation tools in Photoshop to correct your photograph after the fact. Trying to overcompensate for poor exposure also introduces unwanted artefacts, such as noise, and can unacceptably degrade image quality.
To balance my exposure for this image, I first enabled the histogram preview in the preview window. A histogram is a visual indication of the tonal values in your image, from dark to light and across the three R-G-B colour spectrums. To fully explain the histogram display would take far too long in this context, so very briefly, the histogram I’ve pictured here shows the bulk of the pixels in the portrait are rendered as midtones (between pure black and pure white), indicated by the bulge in the white pyramid.
What
I don’t want – and what the histogram shows me – is any pixels rendered out of
the tonal range. In other words, I don’t want pixels to fall off either the left
(dark) side of the graph (this would indicate underexposed areas) or the right
(light) side of the graph (this would indicate overexposure). Adjusting the
Exposure slider a touch to the right, I was able to brighten up the image
without overexposing any parts of it. Uniquely, as the slider moved along, so
the graph changed dynamically, and I knew exactly at which point I had to stop
before pixels would be blown out.
The last step I wanted to take was getting the portrait into the correct colour space. Again a demonstration of colour space specifics would overshoot this review, so it’s enough to know that different colour spaces show more or fewer gradations of each colour based on the size of the colour spectrum it records. The two colour spaces supported by my camera are sRGB (the most common colour space used for Web display and printing) and Adobe RGB, a slightly expanded and potentially more accurate space for my needs (I wanted to show as many tonal gradations of the colours captured as possible).
If
I saved this photo as a JPEG in my camera, the colour space selected at the time
would be recorded with the file. Using RAW, I could make that decision later.
This is an advantage only if you need to use the Adobe RGB space, because Adobe
RGB can be converted to sRGB easily in computer. sRGB, on the other hand,
contains fewer colours than Adobe RGB (its colour space is smaller), so
converting sRGB to Adobe RGB, while possible, does not recover any of the
additional colours found in the Adobe RGB space.
Camera RAW gives you the option of saving your file into numerous other colour spaces, but for the vast majority of applications, Adobe RGB and sRGB are the two you’ll want to choose from. Also, unless you’re using an Adobe RGB-compatible program (such as Photoshop) or monitor, you may be better served with sRGB. Adobe RGB will look “washed out” on an sRGB display, and as a result most Web browsers, monitors and printers default to the sRGB colour space.
Getting closer
At this point I’ve done everything I want to the RAW file, and am ready to
open it up in Photoshop. The changes I made won’t be saved back into the RAW
file (remember, the file is a digital negative), but instead will appear in the
file “translated” into Photoshop by the plug-in. For this reason, I’ve left any
other modifications, such as saturation, sharpness, brightness and contrast
untouched, because I prefer to control these aspects of the picture with
Photoshop’s extensive (and precise) tools.
All that’s left to do then is click OK, and the plug-in goes to work. At this point you’ll see why the Camera RAW plug-in has been earning such rave reviews from users and reviewers alike: speed. From clicking OK to having the translated file open and ready for editing in Photoshop took 11 seconds on my clunky PC. The same conversion in BreezeBrowser took 53 seconds! It may not sound like a long time, but can you imagine processing 100 or more files in a batch? Unless you own a speed demon, you’ll need to leave the PC running overnight.
The technical reason for Camera RAW’s speed is Adobe’s use of its own decoding algorithms for the different types of RAW files supported by the plug-in. BreezeBrowser (and other third party software) relies on the camera manufacturer’s software development kits (SDKs), and are therefore hamstrung if the manufacturer’s software is inept.
The
downside to the trickery is that unless Camera RAW supports your camera, you
can’t use it. In my case, I own the new Canon 10D. Support for the Canon 10D
wasn’t built-in to Camera RAW, even though both products were released a few
days apart. Fortunately I was able to patch one of the setup files in Camera RAW
to make it “read” 10D RAW files, because the plug-in supports the Canon D30 and
D60 (both almost identical to the 10D). The penalty I paid for this is a
slightly inaccurate colour profile for the 10D, which I needed to manually
correct for each image (not difficult in Photoshop but a pain nonetheless), but
otherwise, as you can see, it works fine. Owners of different cameras, however,
may not be so lucky.
The good news is that the functionality of Camera RAW should be bundled with the next version of Photoshop (due for release, according to some sources, in the fall). I would assume then that new camera support will be added incrementally as new models appear on the market, and if that’s the case, I have to wonder why support for new camera’s like the 10D hasn’t already been offered by way of a patch for the Camera RAW plug-in.
Despite this shortcoming, the quality, speed and integration of Camera RAW with Photoshop and Elements 2.0 make this software an excellent short-term investment for photographers working mainly with RAW files. At $99 direct from Adobe it’s not cheap, but the savings in time alone could well offset the cost in a matter of months, if not weeks.
On balance Adobe Camera RAW earns four out of five Go Inside Review Lights, and would have had five if Adobe didn’t miss the trick for Canon 10D owners. Highly recommended.
(four green, one red)
Oops, almost forgot...
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