While most pros have decided one way or another on the topic of raw vs. JPEG, these formats of digital photography capture are still a mystery to most amateurs and there's a lot of blind leading the blind out there.
There's no right or wrong answer to which format you should shoot, except what's the most effective for you and best fit for your desired result, but I hope to provide some compelling evidence to shoot raw, at least if you're serious about getting the most out of your camera and digital files.
Did you know JPEG files sacrifice up to 80% of the original captured information, or that the shadow areas in raw files contain more levels of tonal information per pixel than the tonal range of an entire JPEG file?
The science is clear that raw files contain far more information and flexibility than JPEGs, and new software has rendered the old challenges of processing raw completely moot, as now anyone can get the software necessary to manipulate raw files with virtually the same ease as JPEGs.
The more you know about each format, the less susceptible you'll be to the rampant myths and misinformation there is about either file type and the better you'll be able to decide which format to shoot for yourself.
To be clear, my focus is mainly on the formats as used in digital capture. What other uses they have are generally not covered, though I touch briefly on formats used for printing.
If you're just shooting snapshots of the kids and sending them to grandma, raw is probably not for you and you don't need to read any further. But if you have any desire to get the most out of your images and the expensive sensor you paid for, you owe it to yourself to explore the differences between raw and JPEG.
About Raw
You may be surprised to learn raw isn't actually an image file. It's simply an unprocessed proprietary camera file containing all of the data captured from the sensor, like a film negative. Accompanying the raw file is a sidecar file, or XMP, containing information about the photo which requires software, like Adobe Lightroom, to read and display a preiew of the image. Rather than edit a raw file, you adjust the settings in the XMP file and then export the processed image, much like a lab would develop a film negative into a positive print.
The flexibility and power of raw lives in its "rawness" and ability to be processed and developed to your taste -- like a negative -- and not the camera's tastes (like JPEG). The only settings that affect the recorded pixels of a raw image are ISO, shutter speed and aperture, according to Bruce Fraser, author of "Understanding Digital raw Capture" for Adobe.
Non-exposure settings, such as white balance, contrast, saturation, tone curves, color space, noise reduction and sharpening, ride side-car to the original sensor information in the XMP file and are loaded into the raw editor for you to see as a preview. On the camera LCD, they're loaded specifically as a JPEG preview. Processing software, such as Lightroom, enables you to make development adjustments to the side-car information. Changes aren't actually applied until you convert the raw file into something else, like JPEG or TIFF.
To further get a sense of what raw is, recall that in film you can leave a set of instructions with your negatives and have a lab make prints according to those instructions. You can always go back to the negative with different instructions and make a new print because the adjustments affect only the print, not the negative. Light is simply passed through the negative onto the print paper.
The side-car information "stapled" to the raw file is like the set of instructions for how to process a film negative. A program like Lightroom looks at those instructions and renders a preview -- or copy, if you specify -- of the image, but the original file is never touched. In fact, you can never actually edit a raw file. You can only edit the information about it. That means you can keep changing it without affecting the quality of the original file. This helped earn raw the nickname of digital negative.
Is Lightroom the only way to process raw files? No, there are many other programs, including Photoshop, Aperture and CaptureOne.
Another reason raw files are similar to film negatives is because of their tonal range. Raw files contain at least 4,096 levels of tonal information in each pixel. This means a greater range of tonalities to work with. Raw files that are 14-bit contain 16,384 levels. By comparison, JPEG files contain a total of only 256 -- that's right just 256 -- levels of tonal information per pixel, almost no latitude compared to raw.
The greater bit depth of raw means each pixel has more levels of tonal information to play with -- much more. You have the ability to move the negative around -- to bring detail out of bright highlights or deep shadows, for example -- until you achieve just what you want.
One of the most famous photographers ever -- if not the most famous -- is known for his extensive work in developing film negatives in the darkroom, involving clinical filtering, dodging, burning and other techniques used to develop film negatives into prints that helped make photography into a widely-accepted form of fine art. His name is Ansel Adams. It's no leap to imagine that if Adams were alive today and shooting digital, he'd relish if not prefer the information-rich raw files of today's digital cameras over JPEG.
Advantages of Raw
Original file is never degraded. Adjustments simply travel with the raw file and are never directly applied.
Processing settings, such as white balance, sharpness, noise reduction, tonal curves and color space are not applied at capture, so you can change them however you want in post processing. You, not the camera, are in total control over development.
More exposure latitude, meaning you can adjust more stops up and down without significant degradation.
Original file is 12-bit or 14-bit, containing 4,096 to 16,384 tonal values per pixel -- 65,536 for 16-bit files. This means finer detail, especially in highlights, shadows and tonal transitions, and more dynamic range. The shadows in a raw file alone contain as many brightness steps as an entire JPEG image.
Processes just as easily as JPEG with the right software.
Finest image quality worthy of the largest prints.
You can apply camera color profiles that precisely restore and correct colors for a given spectrum of light to any raw file at any time.
Disadvantages of Raw
Requires special software to process and in some cases view.
File is larger.
File takes longer to process in-camera, can be very slow on pocket cameras.
About JPEG
If the sensor is one of the reasons you paid so much for your camera, you might not like the facts about JPEG.
When you take a JPEG photo, rather than retaining all of the information from the sensor, the camera makes certain decisions regarding things like white balance, contrast, even sharpening, then bakes them into the file and discards all of the other data -- about 80 percent of it, according to some calculations. There's not much original sensor information left in a JPEG. The camera then compresses the finished image into a format that almost any computer can read. Every JPEG that comes out of the camera is done: 400 degrees, three hours, dry as a goose, stick a fork in it.
As Fraser put it:
"When you shoot JPEG, you’re trusting the camera’s built-in raw converter to throw away a large amount of the captured data in a way that will hopefully do the image justice. This is exacerbated by the tendency of most camera vendors to impose a fairly steep contrast curve in the raw-to-JPEG conversion in an effort to produce a JPEG that resembles a transparency. In the process, they throw away about a stop of usable dynamic range, and you have essentially no control over what gets discarded."
If raw is a digital negative, think of JPEG as a digital slide. The main difference is with digital, raw gives you the ability to further refine sharpness and noise, something not possible with film. If raw is writing in pencil, JPEG is writing in pen. Editing a JPEG is like trying to manipulate a painting that's already dried.
A JPEG file that comes out of the camera is already the second generation of the original sensor information, and when you make even the slightest edits to that JPEG in any program, Lightroom or otherwise, the output becomes the third generation. With raw, the first-generation information is retained from camera, and any changes you export from the raw file are only the second generation, and you can make as many second generations as you want from the same raw file.
More JPEG Limitations
If you're thinking the non-destructive editing of Lightroom saves the day, understand that Lightroom makes non-destructive edits only in the sense that what you see is a preview, but when you export the changes, which is necessary for anyone else to see them on say a Web page or print, Lightroom still must render the changes onto an already-processed JPEG that doesn't have nearly the latitude of a raw file.
"JPEGs offer fairly limited editing headroom—large moves to tone and color tend to exaggerate the 8-by-8-pixel blocks that form the foundation of JPEG compression—and while JPEG does a decent job of preserving luminance data, it applies heavy compression to the color data, which can lead to issues with skin tones and gentle gradations when you try to edit the JPEG," says Fraser.
Remember that raw pixels have a lot of depth of information -- thousands of levels. You could "flip through" those levels to bring out just the detail you want. JPEG has 256 levels of tonal information, not thousands. There's a teeny tiny bit of leeway for you to make some edits without highly noticeable degradation, but not much.
JPEG is still a good file, when it's exported from a quality raw file or when it requires almost no post processing. But contrary to what you might think, generally all images require processing to get to a professional standard. When you work with raw, you have to output most images as JPEGs so labs and computers can read them. A JPEG contains enough information to make a fine print. I for one covert all my raw files to JPEG for finished products so they can be displayed on the Web and on clients' computers because JPEG is high quality and portable. But it offers less latitude for processing. I do all my work on the raw file, where I have full flexibility and quality, and then compress into a JPEG.
Advantages of JPEG
Faster processing, since the settings are final and baked in at the moment of capture.
Smaller files for more economical storage.
Requires no processing or conversion to view. This makes it a fast solution for proofing and increases compatibility with devices.
Still has minor development latitude.
Quality worthy of large prints.
Disadvantages
All edits degrade the image in some way.
Discards about 80 percent of the original sensor information.
Image is captured as a final product, with limited development latitude.
Original JPEG file is 8-bit, containing only 256 steps of brightness from white to black, compared to raw's 4,096. This means less available detail in shadows and less dynamic range.
Summary
Photographers tell me this same story all the time: "If I go out and shoot a perfect JPEG and get it exactly how I want it in camera, with great exposure, great light, great color and contrast, why do I need raw?"
Good question, and the answer is simple: "Perfect" negatives don't negate the qualities of raw. Yes, you got that one shot, maybe 90 to 100% perfect, but what happens 10 years later when you want to go back to that shot and reinterpret it? The JPEG discarded up to 80% of the original sensor information and you have almost no latitude to adjust color or tonality without seriously degrading the image. With raw, there'd be virtually no limit to what you could do with the file, and new software unlocks more raw file potential every few years.
Also, while the JPEG you shot yesterday may stack up well among files from today's cameras, it won't against even JPEGs 10 years from now. But raw will continually benefit from advancements in processing that extract more and more information out of the same file.
I know this story too well first hand. In the early years of digital, I shot mostly JPEG because there wasn't a practical raw editing system like the tools available now, and I didn't really understand the benefits of raw. I shot in fantastic locations like Alaska. Thank God I shot a few raw frames of Mt. McKinley, but sometimes I still kick myself for shooting mostly JPEG. I can't go back and apply new developing tools and techniques, like color profiling. I can't play with as much dynamic range or bring out as fine of details. There's simply nothing you can do to manipulate a JPEG without damaging the original file.
With the wealth of tools today and the techniques I know, I could do so much better processing my old files if they were RAW. This is one of the main reasons I'll never rely on JPEG again. There's just too little potential for the file.
"JPEGs are relatively inflexible files -- we may see improvements in their handling, but any such improvements are likely to be modest. Raw converters, however, have undergone radical improvements...and there's little reason to think that the next 10 years won't see similar improvements. Shooting raw will allow you to exploit these improvements as and when they happen," Fraser adds.
Does that mean you "need" raw? I don't know. Like I said, it's a choice and a different approach to shooting -- one in which the camera makes the developing decisions (JPEG), or one in which you do (raw).
If you're just a pocket snap-shooter, you can stick with JPEG. If you don't understand photography and simply don't care, raw is only going to unnecessarily complicate your workflow, if you have one. JPEG requires no processing and is easily read on any device. Also, your camera will shoot faster on JPEG than raw.
Myths
People love to argue that you can't see any difference in a print. That may be true on a dot-for-dot level. To print, you must compress the raw into a JPEG, reducing it from 14 or 12 bits to 8.
Others claim you can't see a difference on screen, that you can never fully use the color depth or dynamic range. That's not true. While you may not see the differences with your eyes, they're still real in the file.
Seeing all of the raw information at once has never been the point of shooting raw. Raw gives you a lot more information to play with and thus more development potential, more than JPEG allows, to achieve the best version of the file possible, which in turn makes it possible to create a print that better meets your vision, even if the dot-for-dot quality is the same on screen and in print.
The purpose of shooting raw is not so you can fix mistakes later. Taking that approach immediately degrades your photography because you don't care about the quality of the original capture. If you're off by even a half stop or more on exposure, correcting it in raw will still introduce noise that will take work to remove.
The true purpose of raw, in my opinion, is to put the most quality possible into the original image, giving you the highest quality of information to work with, thereby increasing the ability to generate a better final image. A bad exposure in RAW is still just a bad exposure. You simply have more latitude for editing it, but not enough to restore detail or light not captured.
There are other phony reasons for not liking raw. One is the idea that it's more work. With programs like Lightroom that read raw just as easily as JPEG, there's nothing inherent to the raw file that takes significantly more effort to process -- more time in some instances, maybe, but the simple adjustments like sharpening and noise reduction, which are likely to be the same across large groups of images, can be batch applied as the images are imported from the memory card. Simple corrections of white balance and color in raw can take painstaking efforts to reproduce in JPEG and will most likely degrade the image.
The most work I remember ever putting into a file was trying to nuance a nice black-and-white version out of a color JPEG without degrading the original file. I did extensive clinical dodging and burning in various parts of the mountain scene. Had the file been raw, I could have accomplished the same thing with Nik Silver Efex and brushes in Lightroom in a fraction of the time, and it would've been non-destructive.
Having a "perfect" negative doesn't negate any qualities of raw. Adams, who literally wrote the book on negatives, was a stickler for processing perfect negatives into perfect prints, usually through extensive darkroom techniques. He wasn't known for shooting slides or printing unprocessed negatives, nor is it likely he'd recommend it. As much art lies in the development of an image as it does in the capture. More development potential has never hurt any file that I've known.
Said Adams, "The negative is the equivalent of the composer's score, and the print the performance."
If you'd like to learn more about how to use raw, please contact me for one-on-one learning.
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