How to Choose Photo File Format for Digital Photography?

Digital Photo Formats Selection Tips

There are so many RAW file formats in the marketplace that it’s becoming a major problem. Here are just some of the RAW filename extensions that indicate different and incompatible formats. 

• Nikon—NEF 
• Olympus—ORF 
• Fuji—RAF 
• Sony—SRF 
• Canon—CR2 
• Pentax—PEF 
• Generic—DNG

Since many digital cameras offer more than one image format, here are some things that might help you select the best one for your needs. 

JPEG

JPEG is the default format used by almost every digital camera ever made. Named after its developer, the Joint Photographic Experts Group (and pronounced “jay-peg”) this format often lets you specify both image size and compression. 

At the moment you capture an image in this format a processing chip in your camera manipulates it based on the camera settings you used and then compresses it to reduce its size. The changes made to the image cannot be undone later because it’s the final, altered image that is saved in the image file. Some of the original image data is lost for good. 

RAW

RAW is a format that’s available on many cameras, especially SLRs. One of Ansel Adam’s better know expressions, drawn from his early experiences as a concert pianist, was “The negative is the score, the print is the performance.” In digital photography, the image file is your score and your photo-editing program is where you perform. For the highest possible quality, you want to start with the best possible score—a RAW image file. 

These files contain all of the image data captured by the camera’s image sensor without it being processed or adjusted in any way. This lets you move the images to the computer and interpret this data the way you want to instead of having the camera do it for you. 

When you want total control over exposure, white balance, and other settings, this is the format to use because only four camera settings permanently affect a RAW image—the aperture, shutter speed, ISO, and focus. Other camera settings are saved as metadata and affect the appearance of the thumbnail or preview images but not the RAW image itself.

With many cameras, you can capture RAW images by themselves or with a companion JPEG image that gives you an identical high-quality RAW file and a smaller, more easily distributable image file. Both the RAW and JPEG files have the same names but different extensions. The latest applications such as Lightroom have made working with RAW images so easy this is no longer really useful and the duplicate JPEG images just take up room.

One thing to keep in mind is that RAW images are not always noticeably better. Where they shine is when you have exposure or white-balance problems. Because RAW images have dramatically more information to work with you can open up shadow areas, recover lost details in highlights, and make fine adjustments to colors. 

Storage Capacity The number of new images you can store at the current settings is usually displayed on the camera’s monitor or control panel.

DNG

DNG (Digital Negative). Cameras companies have introduced many different, and frequently changing, raw file formats. For example, one source states that there are over 140 RAW formats with more coming—some of them specific to a single camera model. On top of this, manufacturers are often pointlessly secretive about their specifications so there are almost always RAW files your software can’t read—at least until someone reverse-engineers the formats so they can support them. 

This lag time and inconvenience can be laid at the doorstep of the camera companies. These proprietary RAW files are at risk over time since companies come and go and interest waxes and wanes. One solution to this growing problem is a new Adobe format called the Digital Negative (.DNG). 

This publicly defined and openly shared format for RAW files is an attempt to ensure that you will be able to access your image files in the future. If your camera doesn’t capture RAW images in this format, you can convert them to DNG using a program such as Photoshop or Lightroom. When you do so, you can even choose to store the original RAW image inside its DNG file so you can extract it at some future date should you need it. 

The DNG format is supported by Photoshop and other Adobe products, some other software companies, and a number of camera companies. As with all things in computing, only time will tell if the format becomes widely accepted or gradually fades away. 

TIFF

TIFF (tagged image file format) is a format that’s often used to exchange files between applications and computer platforms. It’s supported by virtually all paint, image editing, and page-layout applications. TIFF files tend to be larger than both JPEG and RAW images and can be saved using either 8 bits or 16 bits per color.