RAW Files: Digital Manifestations of the Emperor’s New Clothes

RAW Files: Digital Manifestations of the Emperor’s New Clothes

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What’s all the fuss and hype about RAW files? Let’s look at a little story as a comparison.

The Emperor’s New Clothes

The Hans Christian Andersen story of an incredibly vain King is an amusing tale with an interesting moral.

One day the king, who was very fond of fine clothing, was approached by two slick-talking swindlers. They posed as weavers, and they said they could weave the most magnificent fabrics imaginable. Not only were their fabrics uncommonly fine, but clothes made of this fabric were invisible to anyone who was unfit for office, or who was unusually stupid.

“Those would be just the clothes for me”, thought the Emperor. “If I wore them I would be able to discover which men in my empire were unfit for their posts. And I could tell the wise men from the fools.” As the story goes, the king bought into the story and the clothes. As a result, the people of the kingdom discovered more about their king than they ever cared to know.

RAW Files: Digital Manifestations of the Emperor’s New Clothes

Ignorance of the truth sometimes comes at an embarrassing price.

RAW Files

The truth occasionally gets lost in marketing hype, even in photography. How many times have you heard the claim that vast amount of visual information can be seen in RAW image files? There’s a major problem with that claim, the same problem that “exposed” the king in all his vanity. The claim ain’t exactly accurate.

RAW files do indeed contain all the information collected by a digital camera’s image sensor. But the file’s information itself cannot be viewed because the RAW data is not an image at all, it’s merely numbers.

Only when these numbers are parsed (interpreted) as colors and tones by special software can they display any visual information. RAW Interpreter software builds an initial visual image from the data in the file.

The RAW image, just like the ill-informed Emperor’s clothes, doesn’t actually exist until the file data is interpreted. There is no such thing as a RAW image, only RAW data.

RAW Files: Digital Manifestations of the Emperor’s New Clothes - interpretor software

RAW Interpreter software includes Adobe’s Camera Raw and Lightroom, ON1’s Photo Raw 2018 and Alien Skin’s Exposure3, among others.

When you do open a RAW file in Camera Raw, Lightroom, ON1 Photo Raw, Alien Skin Exposure 3, etc., the image you initially see on the screen is actually based on the camera’s built-in JPEG expression of the RAW data; a mere rough draft of the file’s potential information. The camera’s exposure settings (recorded along with the RAW image) determine the file’s initial appearance on the computer monitor.

Once this initial image appears on the monitor, each RAW Interpreter software provides a fairly exhaustive array of color and tonal sliders that can shape the data into a variety of interpretations. Each interpretation can be saved in JPEG format and published for others to see. Folks who shoot and publish JPEGs directly out of the camera are really shortchanging the file’s potential and leaving important color and detail on the cutting room floor.

Emperor Raw beef With vegetables - RAW Files: Digital Manifestations of the Emperor’s New Clothes

The RAW Truth

The term RAW is not an acronym for some technical phrase nor is it a reference to some uncooked food. It is merely a coined word describing the collection of undeveloped (latent) image data from the camera’s image sensor. This data file contains all the raw chroma and luminous data extracted from millions of light buckets called image receptors located on the camera’s image sensor. Each light bucket is covered by a blue, green, or red filter.

Emperor 4k bayerarray - RAW Files: Digital Manifestations of the Emperor’s New Clothes

Individual image sensors are like small light meters, each covered by a red, green, or blue filter. The Bayer filter array uses more green filters than red and blue, relying on the camera’s image processor to interpret the correct light color and intensity for each pixel.

These RGB filters split the incoming light into three channels of information. Each receptor records the strength of the filtered light as an individual color that will eventually form a single pixel in the image.

While the initial grid of receptors is covered with more green filtered buckets than red or blue, the purpose for this imbalance is a bit too complicated for this article. Suffice to say, the image processor in the camera performs some very complicated math to determine each pixel’s color value and brightness.

Emperor Nikon Camera Back - RAW Files: Digital Manifestations of the Emperor’s New Clothes

A digital camera’s image processor sends RGB pixel values to the camera’s viewing screen to preview each scene prior to capturing the image.

This light capture process begins even before the display is visible on the back of the camera. Every time you reposition the camera to frame your shot, the image processor does its magic again and delivers a new preview of the composition. If your camera is set to display a pre-capture histogram of the scene, this processor data is used to simulate the graph on the histogram.

But the real heavy-lifting happens when you push the shutter button and the image is captured. Once all the individual colors are recorded on the sensor and delivered to the processor, the final image information is preserved on the camera’s hard drive.

Emperor Purple Iris CameraRaw

The individual tonal values (luminosity) of the RAW file were fine-tuned in Adobe’s Camera Raw software to reveal detail not visible in the JPEG file.

In a RAW file, the value of each pixel can be extensively adjusted for hue (color), saturation (intensity), and luminance (brightness). JPEG files record pixels with the same initial color values but the JPEG file format significantly restricts the ability to adjust those values in the editing process. The latitude of JPEG adjustments is significantly limited.

Emperor BahamaBlue Exposure3

The controls in Alien Skin’s Exposure3 Raw Interpreter software provide extensive control over hue and saturation color adjustments.

File Types

JPEG files record each color pixel as an initial luminance (brightness level) and chroma (color) value. When all the pixels on the grid (bitmap) are collectively interpreted in imaging software, a visible replica of the original scene appears on the monitor. If that same image is also captured as RAW information, the values of luminance and chroma are captured in the context of a larger color space and can be interpreted in a wide variety of expressions of the original scene.

Emperor 35mm Negatives

Color negatives are produced from latent images when exposed films are fully developed in photo chemical solutions.

RAW files have been likened to photographic color film negatives in that when they are “developed” (viewed in RAW Interpreter software), the image can be “printed” (published) in a number of unique colors and tonal versions.

But the truth is that because this RAW file is not an image per se, but a record of the light characteristics captured by each of the camera’s light buckets, the original image data contained in the RAW file never gets altered, it only gets interpreted.

The interpretations are records of the luminous and chroma adjustments made to the RAW bitmap pixels. These interpretations are what gets saved as JPEG images.

Unlike the yarn spun by the king’s “couturiers,” RAW data files deliver custom-tailored results and can make you look really smart in a couple of ways. Dress your images for success.

Read more from our Tips & Tutorials category

Herb Paynter is the owner of Imageprep Communications, photographer, author, and print consultant suffering in sunny Ormond Beach Florida. He is an award winning Photoshop plug-in software developer who has been teaching digital imaging and production image editing for more than twenty years. Check his blog The Way Eyes See It, download his iBook Digital Color Photography from the iTunes store or view his digital color video series at Gotta Know Videos.com.

  • Dave Melges

    Lots of good information, but still that one falsehood. “The latitude of JPEG adjustments is significantly limited.”

    That’s almost entirely untrue. Just as many pixels in a jpeg, and you can make them all any color you want. Exactly as much latitude. (except in very specific cases)

    What really does happen in the process of converting your RAW data to a jpeg, is your pixels lose their VARIETY. (which is kind of what you explain in the other excellent article) And that can create some limitations, but in almost all cases, those limitations are invisible. What can really help, is knowing where those limitations DO show up…in things like extreme dynamic range and subtle gradations of (almost) solid color.

    What’s missing in most RAW explanations, is that most people for most pictures gain nothing by shooting RAW. That really IS an excellent example of The Emperor’s New Clothes, because RAW fanboys endlessly repeat that RAW is magically much much better, and people don’t know enough to know they’re wrong. So they repeat that too.

    The whole article is loaded with great information though.

  • Nick Brown

    “But the file’s information itself cannot be viewed because the RAW data is not an image at all, it’s merely numbers.”
    That’s the case with any image format. Or any file format for that matter. They are all stored on disk as sequences of bytes that have no inherent meaning until some software interprets them based on some format specification.

  • Herb Paynter

    Hi Dave. Thanks for your comment. My claim that JPEG images are significantly limited is based on the fact that JPEGs are 8-bit images limited to 256 adjustable shades/tones per color while RAW images (typically 12-bit) provide over 4000 levels of adjustment. Most folks would consider that a significant difference. That’s a boatload of elbow room for editing high contrast images. But hey, if JPEG is serving your well in all lighting instances, go with what works for you. Thanks again.

  • Herb Paynter

    True enough Nick. Since digital cameras are basically computers with an optical lens, they interpret only various combinations of 1s and 0s. But RAW files contain totally unprocessed data directly from the camera’s image sensor which cannot be parsed by simple image processors. JPEG files on the other hand have previously been interpreted by the camera’s image processor. There are no microscopic color pixels in any file format. That visual magic happens only on a display. Thanks for the “truth.”

  • namberak

    … I detect a fellow IT guy … 😉

  • namberak

    I would have to differ here; my Sony a7rii will do a simultaneous RAW/jpeg capture. The compressed RAW file is 43mb (the uncompressed raw file is more than 80mb). The jpeg is about 13mb. Something’s getting thrown away there …

  • Arthur_P_Dent

    So, is this article for or against RAW files?

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  • dabhand

    pixels themselves are only numbers – a screen is no more than a giant spreadsheet with cells containing ons/offs for RGB.

  • dabhand

    The whole argument of JPG or RAW is essentially pointless, the quality of color interpretation of either sources will be compromised if the users output medium does not have the level of quality required to differentiate between them.

  • Albin

    The food comparison is actually interesting: the question is not that at every stage of processing there is some level of kitchen presentation, it’s the potential for different kinds and degrees of presentation. RAW is raw and software provides a full palette of spices and preparation techniques – JPEG is more or less pre-cooked, which is not to say bad food, it can come catered and it can come in a Kraft Dinner box, but it is what it is.

  • Terence McKenna

    This is the photographic equivalent of when some corrects a small grammar error. Sure – ok, but in the end, shoot in raw, and process. The JPEG cuts off lots of info that is useful at the margins.

  • Herb Paynter

    Your point is well taken, and I like the food analogy. The preparation of the ingredients at the very basic level gives much more interpretation to the meal being prepared. Never thought of pixels in a dietary way before, but I like it.

  • Herb Paynter

    I’m very much in favor of RAW processing as it’s like an insurance policy on your pictures. You have an opportunity to call detail out of areas that otherwise would not be accessible.

  • Herb Paynter

    While I agree with your statement, a RAW file provides more of the ability to delineate the tones/colors that individual output devices can reproduce; more tones can be pushed into areas that can reproduce well. True, that (almost) all printing devices can only reproduce 256 levels of each color, starting with 4000 levels gives you more ability to choose WHICH 256 tones will be sent to the printer. Big advantage.

  • Herb Paynter

    But remember, pixels started life as photosites on the image sensor, and those photosites captured lumens of colored light. Those lumens were counted and evaluated for both luminosity and chroma BEFORE they were assigned a particular number designator. So what starts as colored light simply evolves through several numerical matrices before again appearing as colored light. What goes around…

  • Byron Robb

    Concise and more useful that everything else in the comments section. Well said, Terrence.

  • PDL

    So, here we go again.
    Any image digital format is not a real image. Different algorithms on different platforms will display the same image slightly differently than the other. RAW images are not a image unless it is interpreted by a computer — Well the same goes for JPEG or TIFF – your statement is overreach.

    RAW formats give you the user all the information that the camera’s sensor can capture, JPEG gives you the camera’s engineers interpretation of what the sensor has detected. You can change the way the JPEG is handled, but with digital photography, as with film, the users optimal settings do not necessarily remain static. In the film days we had — ah film — that we could go back to and make subtle and not so subtle changes to for optimal result. JPEG’s do not have all the data to allow for bleeding edge manipulation as JPEG throws away data by design.

    As a film analogy here it is: JPEG’s are the equivalent of printing film at the old one hour photo stands (yup I am aging myself) and throwing away the negatives. You are stuck with how the machine processed the print. RAW is not only using the old one hour photo stand, but if you want a different look, you go back and get another image produced — YOUR WAY. Better yet, RAW+Post Processing is the equivalent of having your own darkroom with the capability of doing nearly anything you can think of.

    RAW processing does not really take any more processing than JPEG, you can view RAW files on your computer just like you can view JPEG. You can print RAW just like you can print JPEG. In digital photography it is all about data, the more data the better.

  • Michael Clark

    Assuming you are viewing them on a properly calibrated and profiled device:

    There is only one possible “correct” interpretation of a JPEG image file. So even though the JPEG file is all ones and zeros, there’s only one image that is a “correct” interpretation of it.

    There are a near infinite number of interpretations of the data in a raw file that are all equally valid.

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  • Herb Paynter

    Thanks PD. Except for the initial statement you made, I totally agree with your comment and couldn’t have stated it better myself. Allow me to try to clarify what I stated my article.

    “RAW images are not a image unless it is interpreted by a computer — Well the same goes for JPEG or TIFF – your statement is overreach.”

    While JPEG and TIFF files are “images,” RAW files are merely data files (basically numbers) until Interpreter software (Camera Raw, Lightroom, etc) renders that RAW data as an image. At that point, the file gets exported/saved as a JPEG, TIFF, or PSD image file. The RAW data file never actually becomes an image until it is processed as one.

    As in the food illustration that Albin alluded to below, a cookbook recipe will specify ingredients for a meal, but the ingredients are not the meal, merely the raw materials that must be combined, prepared, and processed into a meal. RAW Interpreter software is the kitchen counter on which the ingredients (the numbers data) are blended and prepared as a meal (an image).

    I should probably get hammered for not carefully thinking through this analogy, but it’s the best I can do at this time of night. Forgive me. Hope this makes some sense.

  • Nick Brown

    No, raw files have been processed as well, just not to the degree jpegs are. And there are plenty of tools that can process raw files from most camera manufactures.

    JPEG is a lossy compression format, meaning information is lost during the conversation format. If you trust your cameras settings (and are willing to tinker with them when needed) that may be fine. But there are additional post processing steps you lose the ability to perform.

  • Nick Brown

    Yep!

  • Nick Brown

    JPEGs, TIFFs, and PSDs are data files as well, they have just been compressed with the camera/post processing removing what it considers useless information.

  • PDL

    JPEG and TIFF are not images, they are datafiles using a common format for display. They both need a computer to display them. What you can export is another file format, that is all, you still need a computer to translate the data into the viewable image on a screen. When I open Explorer or Finder, depending on the platform, and view the image the image I see is the RAW data converted by the OS to make it viewable. The image that I see is not a JPEG.

  • PDL

    All RAW formats are variations of TIFF’s, PSD’s are just another format. If the software is removing data while converting the file, then you need to get new software or set the software conversion parameters to not lose or throw away data. JPEG’s throw away data – it’s in the specification on how JPEG’s work. There have been multiple standards proposed on how to “replace” or “augment” JPEG’s and they have all failed.

  • Robert Molan

    no actually, JPEGs are 8 bit depth which greatly limits the editing, similarly the compressed nature of the image ensures that information is lost in the encoding of the data. If you are happy with the out of camera software render of an image as a Jpeg and don’t intend editing or reinterpreting the image than JPEG is adequate, however the bit depth of the image is greatly reduced from 14 or 12 bits to 8. So is RAW “better”? certainly, the RAW file encodes all the information captured in the image, but it is of no use unless you are willing to spend time developing the image to your artistic taste.

  • Ffaelan Condragh

    I hate to be the one to tell you this, but all digital files are just data. They are 1’s and 0’s. And the same thing van be said for jpeg files. Only a program can view them. If just happens to be a very common program with many clones.

  • Ffaelan Condragh

    If you need to clarify what to wrote in a posted article, maybe you should have written out better.

  • Aankhen

    What a wrongheaded article, hung entirely off what would be a minor clarification of semantics if it weren’t simply incorrect.

  • Aankhen

    Well, for some value of ‘correct’, since it’s based on a misunderstanding, so it doesn’t even have that negligible value.

  • Arthur_P_Dent

    It’s just referring to them as the Emperor’s New Clothes suggests they are not all that great.

  • Andrew C Lund III

    RAW data is ‘all that great’ as long as you know what it is and how you want to process it. Very apt analogy to the ‘Emperor’s Clothes’ by my read 🙂

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