How TIFF, RAW Help Pricey New Digitals Produce Better Pictures
By JOHN COSTON
Staff Reporter of THE WALL STREET JOURNAL May 19, 2005
As a rhinoceros rampages through his neighborhood, a suburban Everyman grabs his fancy camera and shoots. The scene, part of a TV commercial for the Nikon D70, introduces a new kind of digital photographer -- the well-armed amateur.
High-end digital cameras that sell for less than $1,000 -- whether Canon's Digital Rebel XT, the latest Nikon D70 or next month's Nikon D50 -- don't have all the bells and whistles of a professional photographer's $4,000 digital, but these six- to-eight megapixel machines are comparable at their core, offering a menu of file-saving options previously unavailable to most amateurs.
One of those options is what format to use for shooting and storage. As megapixel ratings rise and shutter-lag issues fade, what happens to an image after the decisive moment of capture can determine a lot about the quality of the final photo. To get the maximum performance from a fancy new camera, amateur photographers have to know a little about the "digital darkroom."
How to figure it out? Just as in the days of the chemical darkroom, books, seminars and online discussions are great resources. But here's a primer to get you started:
Most point-and-shoot digitals -- as well as the new high-end ones -- offer the space-efficient JPEG format, often with three levels of quality. Images shot and stored in JPEG (it's pronounced "J-Peg," and it stands for Joint Photographic Experts Group) are easily viewed on a computer or hand-held device, uploaded to the Internet or printed by your local one-hour photo shop.
But there's a difference in quality over time between JPEG -- which is known as a "lossy" format because it discards, and thus loses, some data each time an image is opened on your computer and then recompressed as it is closed -- and formats like TIFF (for Tagged Image File Format) and RAW (as in unprocessed), which preserve all the image data. As debates rage about which shooting format is best (RAW is hot now among chatterers at Web photo sites), a handful of guidelines has emerged.
One classic rule of digital photography is that you should choose a file format for shooting that provides a good balance between, on the one hand, your memory card's capacity and, on the other, the intended end use of your photos and how quickly you can return to your PC or Mac to download the images so your memory card has space for more. The new element in this equation is the option to shoot in TIFF or RAW, each of which uses much more memory than JPEGs because they aren't compressed.
Many pros regularly shoot great photos capable of high-resolution enlargement using the highest quality JPEG. In terms of quality, an out-of-the-camera JPEG is pretty much indistinguishable from a TIFF, though many pros eschew the TIFF format for shooting because it takes up chunks of memory on their camera card with no other real payback at this stage in their workflow.
TIFF's strong suit is that it doesn't discard any of the digital image data. As a result, even pros who shoot in JPEG often make a point of saving a "master" image in TIFF for editing and reuse. Another "lossless" storage option for your master is PSD, the native format of Adobe's Photoshop, if you use that software.
Once you have the master, you can edit and print different versions of your image depending on your needs. If you want to put a photo on the Web, for instance, saving the image as a JPEG at 72 ppi (pixels per inch) would work fine. If you plan to print an enlargement, a TIFF in a range from 260 to 300 ppi at the desired print size, such as 5 by 7, makes sense.
Shooting RAW is another option. RAW format is unprocessed data, or the closest you can get to a digital "negative." It takes up more space on a memory card than a JPEG, but only about half as much space as a TIFF, and many photographers who used to shoot JPEG have switched to RAW to gain wider latitude in the processing phase. After shooting in RAW, you can adjust the color or sharpen the contrast of an image directly on the unprocessed "negative" after you transfer it to your computer.
JPEG, TIFF and PSD are already institutions in the graphic-arts world, but RAW is relatively new and may seem daunting to amateurs. What's more, last month, a group of photographers launched openraw.org1 to draw attention to the "RAW problem." What's that? When camera makers offer RAW, it's often tied to their particular software, and different makers have distinctly different RAW formats and in some cases are dropping support for their previous versions. Openraw seeks what it calls the RAW Solution: "We want camera manufacturers to publicly document their RAW image formats -- past, present, and future."
But third-party software like Photoshop is helping out on the compatibility front, plugging into a growing number of camera makers' RAW formats, and making RAW more accessible.
There's also the cool factor. While showing up with one of the new high-end digital cameras is likely to draw envious looks from the point-and-shoot crowd at weekend soccer games, being able to say, "I'm shooting RAW, thank you," could win you a nod from the pro who shoots real rhinos in Africa -- and who may well use one of these lighter, smaller cameras for his own weekend photos.
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