Smartphone photography has moved on quite a lot in the past couple of years, so far in fact that flagship handsets are now touting the ability to save high quality RAW images. Photography enthusiasts no doubt associate the RAW format with professional photography, while the rest of us probably view it as just another setting in a growing list of features. Today we’re going to break down exactly what the RAW format is and whether you should bother taking pictures in it.
It’s in the name
The name RAW actually gives us a pretty good idea what it’s all about. A picture saved as a RAW image is simply the raw data coming directly from the image sensor, unprocessed, unedited and uncompressed. This is quite different to JPEG, the very common image format that your smartphone and other camera’s default to, which is a lossy compressed format that uses algorithms and clever tricks to remove bits of data that aren’t strictly needed. As a result, RAW image files are significantly larger than JPEG’s, often 3 to 6 times the size, which is definitely something to consider when picking between the two. This larger file size also takes considerably longer to save, so taking repeated quick shots in RAW can be impossible if your hardware isn’t up to it.
Foundations of Vision The data lost with JPEG mainly consists of hard to detect high frequency textures/details.
The reason RAW files are so much larger is because they store up to 12-bits of red, green, and blue color data per sensor pixel location compared with the fixed 8-bit levels of brightness with JPEG, although this varies on the image sensor and connected processing hardware. Your smartphone or DSLR will come fully loaded with its own processing solution built in (firmware), which will use this data and sharpen up the image, process the contrast and dynamic range, and then export this to a JPEG all at the click of the shutter. If you see handset manufacturer updating their camera quality with a software update, this is what they’re making tweaks too.
Interestingly, a basic RAW image will often appear lower in contrast and not as sharp as a processed image. However, if you don’t like the manufacturer’s choice of processing or want to make these type of adjustments yourself, then you’ll want to shoot in RAW. It’s also important to note that RAW isn’t an image format in the same way that JPEG is. It contains all of the information needed to create an image based on data from the sensor, but doesn’t present this in a per-pixel data format that you would typically associate with an image of a certain resolution. You’ll need special software to view, edit and print RAW files, and images will (almost) always be exported to another type of format for uploading to the web or printing. Smartphones with RAW support, such as the HTC 10, will still output a JPEG version along with the RAW data for users to view, share, and upload.
Left: A processed JPEG image. Right: An example of what you might see when opening a RAW file before any processing is applied.
RAW, what is it good for?
With all this extra data, RAW is the format of choice for making major edits to your pictures. One of the major benefits of RAW is the ability to better adjust the picture’s white balance to fix under or overexposed images, while still retaining high levels of detail. This is all thanks to the high RGB bit-depth data that is retained across the whole picture. JPEG, on the other hand, has already thrown away much of the lower contrast information that your eye finds difficult to detect, but this may lead to noticeable artifacts when adjusting the white balance or color levels in editing. You might also see additional noise in a heavily compressed JPEG image, known as compression artifacts, as more and more data is discarded in favor of a smaller image size.
While you can certainly adjust the white balance, contrast, and dynamic range of a JPEG image with pleasing results, RAW lends itself to a much higher number of edits before the quality begins to degrade. As I mentioned before, those minor contrast difference losses with the JPEG format can become much more noticeable if you apply multiple white balance and color changes to an image. With RAW you can also apply more powerful custom enhancements, such as de-noise or sharpening algorithms, to the original image. You won’t be able to produce these custom results if you’re applying a filter to an image that has already been given a sharpening pass from the camera’s firmware.
Another benefit of the RAW format is that you’re able to export to any “color space” you want. There are a variety of different models out there, some of which you may also recognize if you’ve read up on display calibration. sRGB is suitable for most web content, but professional services, such as magazine or poster printing, may use the Adobe or ProPhoto RGB models. With RAW you can export to any of these you like, depending on what you want to use the image for.
Essentially, RAW opens the door to much better editing tools, but it requires a lot more work than just letting your camera handle the image processing. So, if you’re planning to upload your phone’s pictures straight to Facebook with minimal hassle, then there’s absolutely no point in shooting in RAW. Firstly because Facebook doesn’t understand RAW, and secondly if you’re not processing and editing the picture manually, then you may as well let your phone handle that for you as soon as you take the picture. But if you’re looking to make the most of your pictures with some post-editing, then you’ll certainly want to shoot in RAW.
What RAW can and can’t do for you
With all of the above being said, it should be clear that shooting in RAW isn’t automatically going to make your pictures look any better, it’s just there to allow for superior editing. Furthermore, RAW isn’t going to introduce additional detail or dynamic range into a picture that your camera’s image sensor isn’t capable of capturing anyway. Therefore, when we’re dealing with smaller, typically noisy smartphone image sensors, RAW isn’t going to boost the image quality to match a high-end DSLR camera.
Another way of looking at it is that a JPEG taken straight from a high quality DSLR camera will still look better than an edited RAW image captured from a cheap point-and-shoot or a smaller smartphone image sensor. So when it comes to smartphones we really need to ask ourselves if the sensors are good enough to justify shooting in RAW at all.
To put this to the test I’ve taken an HTC 10 out for a spin, complete with the latest camera quality update. I’ve capture a selection of pictures in both RAW and JPEG and also done some very basic editing to the pictures to see if the camera is actually capable of capturing enough detail to make editing worthwhile. Of course, I’m not going to be able to make my RAW edit look exactly like HTC’s algorithm and that would also sort of defeat the point. Instead, I’m going to aim to closely match HTC’s color pallet and target a realistic rather than artistic look to see if even an amateur editor like myself can benefit from RAW. Fortunately, the HTC 10 also offers up the ability to automatically enhance RAW files and export them as JPEG’s with better dynamic range and detail, so we can test what improvements, if any, HTC’s specially designed RAW enhancements offer when compared with its default JPEG processing. While we’re on the subject, here’s a sample of the type of enhancements that HTC offers its users (click to enlarge):
At a casual glance there really isn’t much to tell between the regular JPEG and HTC’s RAW enhanced pictures, suggesting that the HTC 10 isn’t throwing in much in the way of post-processing or color alterations. A zoom in to the 100 percent crops reveals a marginal increase in detail when exporting from RAW and some deeper looking blacks, but this probably owes more to the extra use of a sharpening filter and slightly more contrast than anything else. Unfortunately, we can also easily spot sharpening artifacts and extra noise introduced in the sky, which really isn’t very good at all.
OK, so the simple one button editing option is a little underwhelming and isn’t really the sort of solution that RAW enthusiasts would be after anyway. The more important question is can we do better with these smartphone files if we really want to get creative? While it’s certainly a lot more work, the answer, at least in my experience, is yes. I’ll leave you to judge the results (and my limited editing skills) for yourselves, but here are a couple of crops and edits that I’ve made by doing nothing more than adjusting the exposure, white balance, and color temperature of these pictures using some free RAW editing software. No filters, no sharpening, no photo-shopping. Incidentally, these are all also options that you’ll find in the HTC 10 camera’s manual mode.
The final and arguable most useful aspect of shooting in RAW left to cover is the ability to correct over and underexposed pictures. We know that smartphones can definitely have problems with this, and those getting to grips with manual or pro camera modes may find the ability to correct errors especially useful. I shot this deliberately overexposed picture of a small valley and have attempted to improve the exposure of both the default JPEG and RAW images, to try to demonstrate how fixing this problem in RAW is easier than it is with an already converted JPEG file.
While my JPEG restoration does a passable job of sorting out the overexposed foreground, it’s pretty much impossible to bring back the blue of the sky using basic editing tools. You can also see some artifacts and odd colors starting to creep in around the cloud line, simply because the data required is missing from the compressed JPEG file. Interestingly, the HTC 10’s Raw Enhancement button makes some much more drastic changes to the picture to sort out the exposure than before, and does a pretty good job as a result. However, you have to manually adjust the exposure and white balance yourself if you really want to bring back the blue in the skyline. Either way, we can conclude that shooting in RAW, even while using a smartphone, is the best way to be able to correct any exposure mistakes.
Hopefully this article has given you some insight into what RAW is, and what the format is and isn’t useful for. To sum up, shooting in RAW is only worth while if you’re going to be doing a fair bit of manual editing yourself. The one click “enhancement” button found in the HTC 10 has it’s uses, but it isn’t going to drastically improve the look of every picture that you take. Not to mention that the files take up considerably more storage space. If you’re going to be quickly uploading your pictures to social media or sharing them online then sticking with JPEG is definitely the sensible choice.
What about yourselves, have you found the manual modes and RAW shooting options included with today’s modern flagships useful at all?