To describe an image file the word "raw" seems self explanatory - unprocessed, in contrast with compressed formats like jpg.
But mostly we see "raw" written as RAW. Is the use of block capitals merely to bring it into line with JPEG, TIFF etc? Or is RAW actually a mnemonic? I can't find any info on this, maybe one of you scholarly Nikonians knows the answer.
Joint Photographic Experts Group -> JPEG Tagged Image File Format -> TIFF Read As Written -> RAW ?
Here’s a wild guess. If “raw” was written as a normal adjective, less enlightened people might use it as a generic word and not recognize its precise meaning (sensor data that needs to converted to an image file for viewing or further processing). I have heard people say (in Finnish, though) that “these are just raw jpg images from my camera”, meaning images as the camera created them.
Also, as you suggest, because most or all other file formats are labeled with acronyms, it makes sense, for the sake of consistency, to write “raw” with all caps to make it stand out from the body text.
Fri 23-Jul-10 08:00 AM | edited Fri 23-Jul-10 08:12 AM by jrp
"Read As Written" was an intelligent guess, however "RAW" has the same meaning of "raw" such as in "raw meat" It is not an abbreviation or acronym like JPEG (Joint Photographic Experts Group) as you pointed out.
Digital cameras generally perform some digital processing to the output signals from the image sensor to create JPEG images, loosing some data. On the other hand, RAW is a data format which records "uncooked" output signals from the image sensor, that is, without any processing; hence RAW. And by the way, that is why the RAW files are always much larger than JPEGs
Antero's suggestion as to why it mat be written in capital letters (UPPER case) is very plausible.
Here is an article that explains why is most always preferable to shoot in RAW format.
A camera raw image file contains minimally processed data from the image sensor of either a digital camera, image scanner, or motion picture film scanner. Raw files are so named because they are not yet processed and therefore are not ready to be printed or edited with a bitmap graphics editor. Normally, the image is processed by a raw converter in a wide-gamut internal colorspace where precise adjustments can be made before conversion to a "positive" file format such as TIFF or JPEG for storage, printing, or further manipulation, which often encodes the image in a device-dependent colorspace. These images are often described as "RAW image files" based on the erroneous belief that they represent a single file format. In fact there are dozens if not hundreds of raw image formats in use by different models of digital equipment (like cameras or film scanners).
Raw image files are sometimes called digital negatives, as they fulfill the same role as negatives in film photography: that is, the negative is not directly usable as an image, but has all of the information needed to create an image. Likewise, the process of converting a raw image file into a viewable format is sometimes called developing a raw image, by analogy with the film development process used to convert photographic film into viewable prints. The selection of the final choice of image rendering is part of the process of white balancing and color grading.
Like a photographic negative, a raw digital image may have a wider dynamic range or color gamut than the eventual final image format, and it preserves most of the information of the captured image. The purpose of raw image formats is to save, with minimum loss of information, data obtained from the sensor, and the conditions surrounding the capturing of the image (the metadata).
"raw" is a generic term for the raw data output by a camera. Each camera manufacturer has its own proprietary output format, i.e., its particular way of representing the data bits in a file. NEF, CR2, PEF, etc., are file extensions for the files produced by different camera manufacturers (Nikon, Canon, Minolta. etc.). File extensions are usually written in upper case (like DSC0001.NEF), although computer operating systems like Windows are case insensitive and would be perfectly happy with DSC0001.nef. The file formats are different, but they are all "raw" in the generic sense. To avoid confusion when writing about raw camera data, I would always write "raw" in lower case and file extensions like NEF in upper case.
But that doesn't answer the original question: how did the practice of writing RAW get started?
>"raw" is a generic term for the raw data output by >a camera. Each camera manufacturer has its own proprietary >output format, i.e., its particular way of representing the >data bits in a file. NEF, CR2, PEF, etc., are file extensions >for the files produced by different camera manufacturers >(Nikon, Canon, Minolta. etc.). File extensions are usually >written in upper case (like DSC0001.NEF), although computer >operating systems like Windows are case insensitive and would >be perfectly happy with DSC0001.nef. The file formats are >different, but they are all "raw" in the generic >sense. To avoid confusion when writing about raw camera data, >I would always write "raw" in lower case and file >extensions like NEF in upper case. > >But that doesn't answer the original question: how did the >practice of writing RAW get started?
A complete waste of Bandwidth and into the bargain gobbledegook?
Traditionally, file formats are often written as capitals: TIFF, JPEG, DOC, ZIP, even though they are generally lower case when they appear in file names. By extension, a generic file format such as RAW could be written as RAW. As another poster has pointed out, without the capitals it is confused with raw=not refined by post processing.
The way language works is that usages grow up and solidify when they need to. Many British writers use 'program' for a computer program, but 'programme' for a theatre programme, because it makes a distinction which makes sense to them. Because RAW can plausibly be spelled with capitals, and because it needs to be in order to avoid confusion, the usage has grown up in that way.
Remember also that while some file formats are mnemonics, such as JPEG, not all of them are. DOC is short for document but PCX, the old PC Paintbrush file type, isn't short for anything.