In the context of digital photography, there are two terms you probably hear frequently: DNG and RAW. What are they?

In short, they both are file formats of digital photo, but there are several things differing them. Understanding the differences between the two will help you a lot in the post-production process. RAW, as you have probably known, is the image format that stores all information captured by digital camera sensor. No data is compressed when you shoot in RAW.

DNG is also considered as a RAW format since it also stores all information captured by the camera sensor without any date is compressed. So, where is the difference?. Be cool, let’s discuss them one by one.

RAW

The term of “RAW” might tends more popular than DNG. RAW is an image format that stores everything captured by the camera sensor. In RAW, there is no data is compressed. It’s an opposite to JPEG which compresses several data captured by the camera sensor. As a result, a JPEG file typically has a smaller size than RAW.

The problem about RAW is that it’s a proprietary format and each camera manufacturer has its own file extension for RAW. For instance, Nikon has a .NEFfile extension while Canon has a .CR2file extension. Since RAW is a proprietary format, not all software have the capability of opening as well as editing RAW. It will be even worse if a certain camera manufacturer releases a new format for its RAW.

That it why the vast majority of RAW processor software like Lightroom and Darktable uses a separated sidecar file to store the settings you made to your photos since a RAW is basically can’t be modified by third party software. The advantage of shooting in RAW is that you can do much things to your photos, without worrying about quality of the original files no matter how many times you edit them. Remember again, when you are editing a RAW file you are basically doing nothing to the original file until you export it. You are just making a sidecar file by making some adjustments to the associated RAW file. Since the settings are stored in the separated files, a good file managements is required to get everything organized.

DNG

As mentioned above, DNG is basically also a RAW format. However, it doesn’t belong to any camera manufacturer. DNG is a proprietary image standard intended by Adobe. What makes it different to RAW is that DNG is a generic format and has a large compatibility with nearly all RAW processing software. Unlike RAW, in DNG, changes can be written directly into the original files instead of sidecar files (although most RAW processing software keep using the sidecar files to store the changes). Thus, your job in managing DNG files is slightly easier than RAW.

DNG itself uses .dngas the file extension. Since DNG is technically owned by Adobe, you won’t find the option of DNG when setting the image quality on your digital however. However, some camera manufacturers like Leica, Hasselblad and Pentax have adopteded this standard and use it in their cameras as their native and supported RAW file format. If you are not a user of the mentioned camera brands, you can convert your RAW files into DNG if you want to work with DNG instead of RAW. And this is the downside of DNG since the conversion from RAW to DNG can takes extra time. This can be significant when converting high-resolution images.

Conclusion

RAW and DNG have one thing in common. They both don’t compress the image information captured by the camera sensor. They both are also proprietary formats. Every photographer has their opinion about which is the better between RAW and DNG and which format they should be using. To decide which format you should be using, you might can check how good the RAW processing software you use in handling them. If it handles both formats just as good, RAW is probably a better option since converting RAW to DNG can takes extra time. The consequence, you need to have a good skill in file management.

The problem is, not all RAW processing software has the good capability in handling certain RAW format. For instance, Darktable — the RAW processing software I use — sometimes experiences problem when handling NEF files, which is never happened when it comes to DNG. There is neither wrong nor right here. Everything is about taste and what kind of tools on the post-processing you have.