So you’ve done the research, read the articles, browsed through your photos, and decided it’s time to go from shooting in JPEG to shooting in RAW so you can get the most quality possible out of your photos. Congratulations, and welcome to the fold!
Things are nice over here in RAW land. And now that you’ve firmly decided once and for all to shoot in RAW, you can stop thinking about file formats and get back to making beautiful images, right?
Well, sort of.
Turns out there’s yet another layer to this file-format cake, and it adds one more twist to the mix: RAW compression formats. Many cameras offer the option to shoot in either 12-bit RAW or 14-bit RAW, and you need to decide which setting to use.
“What?!” I can hear you saying now. “What’s a compression format? What’s the difference between 14-bit RAW and 12-bit RAW files? And why does it matter? Can’t I just shoot in RAW and be done with it?” Yes – and no.
Before I wade into the details, I want to make one thing clear: Your camera is a very capable imaging device, one that would have been the envy of every photographer in the world just a few years ago. You don’t have to understand everything about RAW, JPEG, and other formats to take great shots, and you don’t have to think about file formats if you’re spending time taking photos that you like.
But if you would like to know more about how all this works so you can capture the RAW files that best suit your photographic goals, then by all means, read on. You might want to sit down and grab a cup of coffee, however, because things are about to get a bit tricky!
How camera file formats work
When you take a photo with any camera (DSLR, mirrorless, point-and-shoot, or even your smartphone) a massive amount of color information is captured by the camera’s image sensor. This information is immediately sent to a computer chip that analyzes it, and it’s ultimately saved to your memory card as a picture.
If you shoot in JPEG, a great deal of the captured data is discarded to save storage space and facilitate easier sharing. But if you shoot in RAW, most of that color data is retained. As a result, you have much more flexibility to edit the resulting file in a program like Lightroom or Photoshop. Photographing in RAW does also result in file sizes that are quite large and not at all conducive to emailing. Plus, RAW files need to be converted to a format such as JPEG or TIFF before they can be displayed online.
The file format used by your camera isn’t set in stone. Most cameras – including virtually all interchangeable-lens models on sale today – include a file-format menu, where you can toggle between various format options. However, once an image is captured, you cannot change the file format in-camera; instead, you’ll need to use file-conversion software, and your options may be limited depending on the original file format.
Common file formats offered by cameras
The specific file formats available to you will depend on your camera. However, many cameras allow you to choose between file formats such as:
- JPEG: Every camera offers this format, which stores 256 tonal values for each color but compresses the file in such a way that a significant portion of the photo data is discarded. The JPEG format is ideal for photographers who do not do much editing in Photoshop or Lightroom, and the file sizes are much smaller than RAW, which makes them very easy to share.
- 12-bit RAW lossy compressed: This format stores 4,096 tonal values for each color (red, green, and blue) per pixel, but then throws away some information it deems unnecessary. With your camera set to 12-bit RAW lossy compressed, an algorithm compresses the file so it’s a bit smaller and takes up less space on your memory card. Most of the discarded data is on the right (light) side of the histogram, which makes sense, since digital cameras typically capture much more information in the midtones and highlights to begin with. Thus, there is a great deal more leeway when performing a lossy compression algorithm. Since the algorithm removes some data from a part of the image where there is so much to begin with, the loss of information will not matter to most users.
- 12-bit RAW uncompressed: This format also stores 4,096 tonal values for each color, but it does not throw out any data to shrink the file size.
- 14-bit RAW lossy compressed: This format stores 16,384 tonal values for each color. Note that this is far more tonal values than the 12-bit RAW format is capable of storing. (Why? 12 bit means 2 to the power of 12 or 2x2x2x2x2x2x2x2x2x2x2x2, while 14 bit is 2 to the power of 14, so it’s multiplied by another 2×2!) The 14-bit RAW lossy compressed format discards some data it deems gratuitous to compress the file so it’s a bit smaller.
- 14-bit RAW uncompressed: This is the highest-quality file format most cameras offer. (Some ultra-high-end models do have 16-bit RAW files, but they usually cost a ridiculous amount.) Uncompressed 14-bit RAW files store 16,384 tonal values for each color per pixel and do not throw any data away, giving you the highest possible amount of information to work with in post-production.
So should you use 14-bit RAW or 12-bit RAW?
Looking at the data I shared above, the answer seems clear, right? Just shoot in 14-bit uncompressed RAW because it’s obviously better! Well again, yes and no.
Due to the increase in the amount of data offered by a 14-bit file, the resulting RAW images take up much more space on your memory card and computer and are much slower to load in a program such as Lightroom or Photoshop. If you shoot with a high-megapixel camera like the Canon EOS R5, you can easily get RAW files approaching 100 MB each. The extra information is great when you need it, but it can be quite a burden if you decide that all the additional data is not worth the tradeoff in storage space.
Another issue that comes into play when comparing formats is whether the increased data is useful. Does a 14-bit RAW file really give you more flexibility when editing an image compared to a 12-bit RAW file? It should in theory, but in practice, having 16,384 tonal values for each color could be overkill for most people. If you generally get your exposure correct in-camera and you don’t want to make dramatic color adjustments in post-processing, then you may not need the sheer quantity of data provided by a 14-bit uncompressed RAW-format file.
Real-life examples
Some camera makers have other RAW formats, such as sRAW and mRAW, that actually decrease the pixel count of your images while still giving you the flexibility of a RAW file. But, at the end of the day, one thing is clear: shooting in RAW will always give you significantly more freedom to edit your images than shooting in JPEG. The question then becomes: Which RAW format should you use?
There are benefits and drawbacks to each one, but all RAW types allow you to have an extraordinary degree of flexibility in post-production. Like almost everything in photography, there is no single correct answer to the question, and it is largely dependent on your shooting style and needs as a photographer.
To see how this plays out in a real-life scenario, here’s a picture I took overlooking the Formal Gardens at Oklahoma State University:
I re-shot the same picture using massive over- and under-exposures in four different RAW formats, then corrected them in Lightroom. Shooting these photos as JPEGs would have resulted in unusable files, but RAW gives you so much extra information that you can often salvage parts of a picture that would have been entirely lost otherwise.
The RAW format is useful for much more than fixing overexposed pictures, but it’s in extreme circumstances like this that the real differences between the 12-bit, 14-bit, compressed, and uncompressed RAW formats would be most likely to show up.
This first set of images was intentionally overexposed by three stops. I left the aperture at f/4 and ISO at 100 but increased the shutter speed to 1/30s:
I then used Lightroom to bring the exposure values back down by three stops for a correctly exposed image. Some data has been lost due to clipping, where things are so overexposed there is literally nothing left to recover, but for each picture, I was able to get a decent image for comparison purposes:
I still wouldn’t use these in an actual production environment, but they should give you an idea of how flexible the RAW format really is! All images look virtually identical, but that’s not too unexpected given that these are minuscule thumbnails of 24-megapixel images. To get a better understanding of how the RAW compression formats compare, here is a 1:1 crop of the same section of each photo:
Notice much of a difference? I don’t. That’s not to say there isn’t any difference, just not one that’s discernible to the human eye.
Since the initial 14-bit uncompressed file is more than 50% bigger than a 12-bit compressed image (39 MB versus 25 MB), there is clearly a lot more data to work with, but as this test illustrates, much of that is not likely to matter a whole lot in practical terms. The biggest difference I can see is not due to lossy compression but bit depth, as both 14-bit files show just a few more clearly defined bricks in the sidewalk to the right of the planter.
However, keep in mind that this is a 1:1 crop of a 24-megapixel image. You’re looking at about 94,000 pixels in each section above out of nearly 25 million (about .04% of the total image). If you have to zoom in this far to see any noticeable differences between 12-bit and 14-bit RAW files that were overexposed by three whole stops to begin with, then to me it does not offer a significantly compelling reason to shoot 14-bit RAW most of the time.
To continue with the comparison, here’s the same picture underexposed by three stops in-camera by increasing the shutter speed to 1/3000s:
Since almost no data was clipped, which I could tell by looking at the histogram, adjusting the exposure by three stops in Lightroom results in an image that is virtually identical to the correct one at the top of this section. Taking a look at the 1:1 crops yields a similar result to the first test:
The results here are remarkably similar to the overexposure test, and you should also remember that these pictures have been severely underexposed before correcting them in post. The differences between the corrected images you see above are negligible, and the much smaller 12-bit compressed file gives results that are almost identical to the 14-bit uncompressed.
Choosing a RAW format: final thoughts
While you can’t draw a universal conclusion from just one test, this example does illustrate that shooting in 12-bit compressed RAW still gives you plenty of data to work with when editing your images. As I mentioned at the top of the article, some data is literally thrown away when shooting with a lossy compression format, but in most situations, it’s nothing you are likely to notice.
Only in extreme circumstances – such as when you want to do massive highlight or shadow recovery or if a photo has been severely over- or underexposed – are you likely to notice any practical benefits from shooting in 14-bit RAW.
However, if you are the type of photographer who wants the most possible data in each picture and continually pushes your camera to its limits, I would recommend capturing as much information as possible (i.e., shooting in 14-bit RAW) and retaining every last bit of data (i.e., shooting uncompressed).
A notable caveat here is that the test I performed was just one example, and it’s entirely possible that a different scenario would have done a better job of illustrating the differences in terms of the different RAW formats. When doing this comparison, I tried to pick something that was generally representative of a typical photographic scenario, and not a situation that was far outside the realm of what most people would encounter when taking pictures. If I had over or under-exposed by four or five stops, or shot at higher ISO values, perhaps there would be some significant differences in terms of what each format has to offer, and I don’t want to draw any large-scale conclusions from just one small set of data.
What this test does suggest is that even though 12-bit compressed RAW files contain less photographic information than their higher bit rate counterparts, enough important data remains to give you plenty of wiggle room if you need to apply extreme corrections in post-production.
I have shot with many types of RAW formats for a few years and feel entirely comfortable shooting in 12-bit compressed. I do all my pictures this way, even paid jobs for clients, and have never had a circumstance in which a bad picture would have been salvageable if I had only shot in 14-bit uncompressed.
In my experience, there are plenty of other factors that matter just as much, such as choosing the right lens, nailing your focus, composing your shot, knowing when and how to use external lights, and a host of other things that are more important than eating up your memory cards with 14-bit uncompressed RAW files. If your pictures regularly require the type of extreme editing that can only be saved by heavily editing a 14-bit uncompressed RAW file, I’m going to go out on a limb and say there are probably other things that you need to work on to improve your photography besides choosing the right file format.
Of course, I want to reiterate that the RAW format is beneficial for far more than just fixing images that are way too bright or dark. RAW gives you significant flexibility when editing the colors of an image and allows you to bring out more natural skin tones, display the deep rich blues hidden in a dull gray sky, find the intricate details of a flower petal that would be lost in a JPEG, and perform all sorts of other edits that have nothing to do with making a dark photo a little brighter. Any RAW format is better than none, if you’re the kind of person who likes to edit your images after you take them, but if you want a nice balance between having lots of data while still keeping file sizes down, 12-bit compressed will most likely suffice just fine.
What about you? I’m curious what your experiences have been with compressed and uncompressed RAW. I’d like to hear about your experiences in the comments below, especially if you have encountered times when shooting 14-bit uncompressed RAW has come in handy. The more information we have to work with, the better informed we will all be as photographers!
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