Adobe taps the power of negative thinking

With its Digital Negative project, Adobe is championing an effort to improve photo quality and longevity. If only it were that simple. Photos: Cameras that support Adobe project

Stephen Shankland principal writer
Stephen Shankland has been a reporter at CNET since 1998 and writes about processors, digital photography, AI, quantum computing, computer science, materials science, supercomputers, drones, browsers, 3D printing, USB, and new computing technology in general. He has a soft spot in his heart for standards groups and I/O interfaces. His first big scoop was about radioactive cat poop.
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Stephen Shankland
8 min read
With a new image format, Adobe Systems believes it can improve the quality and longevity of digital photographs--but the software maker faces serious challenges.

Adobe promotes its Digital Negative (DNG) format as a replacement for the profusion of useful--but proprietary--image formats of today's high-end cameras. The San Jose, Calif.-based company believes the industry and consumers would benefit from a unified format.

Now Adobe's challenge is to build consumer demand and find industry allies. So far, only a handful of cameras support the technology, it doesn't ease some of the difficulties of the proprietary formats, and it's not a neutral industry standard.

But the company is patient. "When we announced DNG two years ago, we said that it would be a slow road to adoption. We already have a variety of cameras at different price points supporting the format natively. That's very good progress," said Tom Hogarty, Adobe's digital imaging product manager.

DNG is the byproduct of the ability of higher-end cameras to store data in their own "raw" formats. While most cameras convert their sensor data into images in the JPEG format, raw formats record the unprocessed data. Photographers must use software to process raw into more convenient formats such as JPEG (Joint Photographic Experts Group) or TIFF (Tagged Image File Format).

All digital SLR cameras and several compact models can produce raw images, and enthusiasts and professional photographers have rapidly embraced the technology to gain fine lighting and tonal control for their photos.

A raw deal

Most consumers are happy with JPEG, but raw formats offer considerable advantages.

One is superior dynamic range--the ability to record subtler differences in shading. For each pixel of an image, JPEG stores 8 bits of data describing the amount of red, green and blue light. Raw images record between 12 and 16 bits per color, so images have finer gradations in light levels.

That means a JPEG photo of skier might show a featureless wash of white snow, where a raw image would let a photographer emphasize the snow's subtle shadows.

Raw images also let photographers adjust "white balance," the varying proportion of colors found in sunlight, incandescent light, fluourescent light and other conditions. With JPEG, photographers rely on the camera's best guess about the lighting conditions.

"I shoot 95 percent nature images, and conditions and light are constantly changing. Shooting raw gives me so many opportunities to make adjustments before I start the actual editing process," said Ray Barlow, a hobbyist nature photographer in Grimsby, Ontario.

But raw poses a problem for companies like Adobe, whose bread-and-butter business includes image-editing software such as Photoshop, Photoshop Elements and Photoshop Lightroom. They must write new software to support each new camera model's raw image variation.

"This raw format Tower of Babel is going to explode," said Dave Story, Adobe's vice president of digital-imaging product development. Raw support is a challenge today, but Story argues it's only going to get worse. That's because more camera manufactures will add raw support, to entice consumers displeased that more megapixels from their camera hasn't meant higher-quality images.

The second major motivation for DNG is to ensure raw images will have an archival standard that endures even if camera makers' raw-processing software doesn't work on future computers, or if those manufacturers themselves go out of business.

"There's basically a new format for every single camera model. In 5, 10 or 15 years, how easy will it be to find software that supports those proprietary file formats?" Hogarty asked. "Is there a need for a unique format? Wouldn't it be better if we stored information in a common way?"

That argument appeals to some photographers. "It is a great idea to have a standard for raw images, because who knows where photography will go in the future?" said Holly Yurchison, a Cincinnati, Ohio, photographer who recently began selling family portraits.

Ken Milburn, author of Digital Photography Expert Techniques, likes DNG's longevity. "It makes sense to convert whatever you get out of your camera into DNG just for archival purposes," Milburn said. (Adobe offers a free tool to convert images into DNG.)

Not so fast
Standardizing raw isn't that simple, though. Adobe's DNG plan initially resonated with Doug Meisner, senior product manager of Paint Shop Pro Photo at software maker Corel, who doesn't relish the prospect of decoding dozens of cameras' raw formats. But he became disillusioned.

"When we first heard about DNG, we thought, 'This will be wonderful,'" Meisner said. "We were surprised to find we still had to do pretty much the same steps as we had to do without DNG. Our software still has to know exactly what makes a (Canon) Rebel XT a Rebel XT," he said. "There's very little benefit to us."

Hogarty acknowledged that DNG doesn't cover some aspects of an image. "The DNG file provides all the necessary information to accurately describe the image data, but the tonal controls and algorithms used to manipulate raw image data are not standardized across the industry," Hogarty said.

Apple Computer, which sells raw-image editing software called Aperture, also finds DNG imperfect.

"We do support DNG, but only for those raw formats we currently support natively," said Kirk Paulsen, Apple's senior director of product marketing for professional applications. "When we open up the DNG, because we also have support for the underlying raw file, we can process the image and take advantage of the underlying data."

Another issue: Apple would like DNG better if it were a neutral standard, not one controlled by Adobe, said Rob Schoeben, Apple's vice president of applications product marketing.

Cameras that support DNG

"What would be ideal is if DNG could be turned over to a standards body, opened up and published, so everybody would know it can evolve in same way JPEG evolves," Schoeben said. And standards outlast companies, he added: "Today, you either bet on a camera company or a software company. I think people want to bet on a standard."

Adobe's ownership is an issue for camera maker Olympus, too. "At this time, we have seen no strategy for it to become a de facto standard across multiple platforms or software beyond Adobe," said John Knaur, senior product manager for digital SLRs at Olympus.

Adobe maintains DNG, but it shares full specification details (PDF here) and offers DNG supporters free use-related Adobe patents.

The company also indicated that it plans to relinquish control: "It's more efficient for one or two companies to jump-start a standards initiative, then hand off the results to a standards body, than to begin the process within a standards organization," Hogarty said.

Camera makers weigh in
DNG isn't widespread, but Adobe has won a few allies. Among them:

•  DNG is used in Leica's newly introduced $4,795 M8, the first digital model in the company's decades-old rangefinder camera lineage.

"When we design our cameras, we always think about the option to use the camera for a long time. We have kept the same lens mount for more than 52 years now on our rangefinder cameras. It says something about the brand Leica," said Christian Erhardt, Leica's marketing manager for North America. DNG has that longevity, he argued. "We hope you can open these files for the next 50 years," Erhardt said.

• Ricoh doesn't support raw on most cameras, but in one unusual case--the GR Digital, geared for landscape photography enthusiasts--the company chose to use DNG for image quality, said Jeff Lengyl, marketing manager for Ricoh cameras. But he said average camera buyers are happy with JPEG and aren't interested in the complications of raw formats.

• Hasselblad, a maker of very high-end cameras, initially used DNG in its 39-megapixel H3D, but an update this year removed the support.

DNG couldn't support a high-end feature that would automatically fix color aberrations from the camera lens. Neither could it support future features to correct lens distortion and a darkening problem called vignetting, said Victor Naranjo, a Hasselblad regional sales manager. "That's something at this time we're not able to do, shooting directly to DNG. In the future that might be possible," Naranjo said.

Outside those companies, support is hard to find.

Take Nikon, along with Canon, one of the digital SLR powerhouses. "Nikon currently has no plans to support the DNG format within its cameras," the company said. One concern is that DNG is a slow-moving standard that could slow Nikon's innovation, it added.

Olympus and Canon have looked at DNG support, but won't say whether they'll adopt it. Digital SLR newcomer Panasonic said: "At this moment, we don't plan to support DNG format. But we will watch that format trend."

Espen Hildrup, a photographer in Oslo, Norway, doesn't expect camera makers to fully standardize, because they don't want to lose character such as Olympus' warm colors or Nikon's rich blacks. "By standardizing the raw format, I think these companies (would be) afraid of giving away their own formula, so they will hang on to their own files," Hildrup said.

Raw proliferation
Adobe's Story thinks raw images will spread, so consumers can extract better images from their cameras.

"For a consumer camera, megapixels are not the ultimate goal. We're rapidly reaching the end of the megapixel wars. You can get a 10-megapixel camera for $400," Story said. "We're shifting now to 'How do I get an edge on quality?' That's why raw formats exist. It's starting at the top and working its way down."

Canon, a dominant maker of SLR and compact cameras, sees things differently. Raw image quality on compact cameras isn't necessarily better than JPEG, said Chuck Westfall, Canon's director of media and customer relations. In fact, while the 7.1-megapixel PowerShot G6 supported raw, Canon dropped that support when it introduced the 10-megapixel G7 in September.

Increasing megapixels in a new-generation sensor means each sensor site becomes smaller. That in turn makes it harder to distinguish between signals produced by incoming light and those from random electronic noise in the sensor. Compounding the situation, compact cameras already use smaller sensors than SLRs.

The smallest sensor site on a Canon SLR is 5.7 microns wide, and on higher-end models they're 8.2 microns wide, Westfall said. A G7's sensor sites are less than 2 microns wide, in comparison, and therefore produce more visual noise and are worse at discerning differences in brightness.

"The net result is that even if the G7 offered raw image capture...there would be no discernible improvement in image quality compared to...Superfine JPEG mode," Westfall said.

The photographers speak

Adobe has certainly won some support among photographers.

"As quickly as the technology is advancing in this medium, I am, of course, concerned that at some point my backed-up files will be useless," said Eric Lawton, an amateur photographer in Milton, Pa., who shoots raw images 99 percent of the time.

Barlow believes DNG could be a bridge between the Nikon equipment he owns today and the Canon gear he's contemplating buying.

But Bill Frakes, a professional photographer who shoots for Sports Illustrated, is an illustration of the hurdles that remain. He archives his favorite images in raw, JPEG and TIFF--not DNG. And although he agrees with Adobe's standardization motive, he isn't optimistic it will prevail.

"I would love for there to be a standard out there," Frakes said. "I don't think it's going to happen."