RAW image format: Tech Explained
Smartphone photography has moved on quite a lot in the past couple of years, so far in fact that flagship handsets are now touting... RAW image format: Tech Explained

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.

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.

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.

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.

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.

Wrap up

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.

Sellami Abdelkader Freelance Writer

Computer engineering student at the institute of Electrical and Electronics Engineering in Algeria. Passionate about Web design, Technology and Electronic Gadget.