If a camera produces compressed files for instance, some data deemed superfluous is discarded. Many types of image processing result in loss of data, effectively degrading the quality of the image. Though larger than a compressed image such as a JPEG file, a raw image contains more data than a TIFF image and uses less space. Raw images are high-quality image files that contain the maximum amount of original image data in a relatively small file size.
In other words, a raw file contains all the unprocessed image data captured by the camera’s sensors for each and every pixel, without any embedded software instructions about how that data is to be interpreted and displayed as an image on any particular device.Ī limited but basically effective analogy or model for understanding the distinction is the difference between sending a film off for automatic processing by a commercial machine-with it’s own specific capabilities and limitations-and using your own darkroom where you can control everything from the development of the negative to the way the image is exposed and printed onto paper. Raw files are referred to as such because, unlike many of the more common image file formats that you may recognize, such as JPEG or GIF, they are not processed by the digital camera in any way. The sidecar file takes the name of the raw file, with the extension “.xmp.” Any modification that you make to the raw photograph is written to the XMP (Extensible Metadata Platform) file, rather than to the image file itself, which means that the original image data remains intact, while the XMP file records every edit. The moment you open a camera raw file for the first time, the Camera Raw plug-in creates what is sometimes referred to as a sidecar file in the same folder as the raw image file. Photoshop Elements opens the image in the Camera Raw window. Right-click / Control-click the thumbnail and choose Edit With Photoshop Elements Editor from the context menu. In the Media Browser, locate the camera raw image DSC_5683.NEF. In the Organizer, click the arrow beside the Lesson 04 keyword tag to isolate the Lesson 4 images, if necessary. For the rest of this lesson you’ll be working with a raw image in Nikon’s NEF format as you explore the correction and adjustment controls in the Camera Raw window.
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