RAW vs DNG

As it seemed to me from the comments to this article, among habragraph photographers there are a number of people who did not know (or did not know) about the DNG format. In this topic, I will consider this format in relation to RAW.

Which of these formats is better to use? You may have asked yourself this rather important question. If you have not heard anything about the DNG or heard only briefly, without going into details - it does not matter. That is why I am writing this post. All interested - welcome under cat.

Before writing further, I will make a reservation: in this article I describe the differences only between DNG and RAW. JPEG do not touch.
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What is RAW?

This is a “raw” file recording format, also known as a “digital negative,” which is almost raw data coming directly from the camera's sensor. This word is used to the primary data not only in the photo workshop, but also, for example, in music and video production. Yes, this is not strange, because “raw” in English means “raw”.

RAW itself is not a file format per se. Under this name gathered more than a dozen formats. But since they all work on the same principle, they are called by one common word. RAW is proprietary and tied to the camera manufacturer. That is, each manufacturer of cameras with RAW support has its own file format that is not compatible with others.

RAW format benefits

1. Contains a full preview in JPEG format, processed by the camera (using the settings selected when shooting).

2. In addition to basic exposure information, it can store additional camera-specific data (for example, a focus value).

3. Greater freedom in many processing options. Reserve only needed a small XMP-file.

RAW format flaws

1. Not all programs can open RAW files.

2. RAW formats are fully supported only by camera manufacturers (I remind you that each has its own). Only software that came with the camera can change them (for example, Canon - Digital Photo Professional, Nikon - Capture NX, etc.).

3. Follows from the previous paragraph. Since RAW files cannot be modified by third-party software, all changes made to the file will be stored separately (XMP file).

It should be noted that recently in cameras (especially high-end), the possibility of recording in the so-called “compressed RAW” is becoming more and more common. Such files retain all the charm of full RAW, but take up less memory. At the moment there are two types of such files. Smaller compression removes a quarter to a third of the total volume. The second version allows you to "reset" up to 50-60% of the volume. Let me remind you that all the advantages of RAW over JPEG while not suffering.

What is DNG?

DNG (Digital Negative Specification) is considered one of the sub formats of RAW. This is a proprietary format from Adobe, which was created to store image data in a compatible format, unlike other RAW files. Although DNG was invented by Adobe and is supported in all applications of the company, there are other manufacturers (Pentax (thanks to JStingo ), Leica and Hasselblad) who have adopted this standard and use it in their cameras as the main format of RAW files.

Currently, this format is supported at a lower level than RAW. This is one of the factors that add uncertainty, because it is not known what will happen with the format further. Personally, I’m confident in the power of Adobe to promote it further and, if not to make it an industry standard, then increase its popularity.

What are the benefits of the DNG format?

1. No need to worry about the camera's native RAW format — once converted to DNG, it will work with any software that reads DNG.

2. As a rule, takes less space relative to RAW.

3. The changes made with the snapshot will be written directly to the file, which eliminates the need for additional XMP files. This simplifies file management.

4. Able to store the full original RAW file, which, if necessary, can later be manually extracted.

5. Adobe provides many ways to automatically convert RAW images to DNG format in programs like Lightroom.

The company continues to work on DNG, adding more and more features.

Disadvantages of the DNG format

1. Not all programs can open DNG-files, including those that work with other RAW-formats (although this situation has recently been corrected). This includes software from camera manufacturers (for example, Nikon Capture NX).

2. Converting RAW to DNG takes extra time.

3. Removes some meta data (such as Active D-Lighting and Picture Control) from RAW files, making it impossible to get this data from DNG in the future.

4. Since all changes are written to the DNG file, you must back up the entire file each time you make changes to it.

What is the format to use?

In fact, these formats are equivalent. From both you can equally pull out the picture, export to the desired format, keep processing in the end. Suppose that in the case of DNG it is a bit more expensive in size (although now hard disks do not cost a penny, but still it is very cheap and simple to store huge amounts of information).

Personally, I prefer to use DNG for the following three reasons:

1. Compatibility - it does not matter which camera I use today and which one I use tomorrow.

2. Simplicity - all changes are written to one file.

3. Size - these 15-20% of extra space matter when you have tens of thousands of photos.

Of course, this takes a little more time, but for me the benefits of DNG outweigh the benefits of RAW. The backup process is easier because I don’t have to worry about choosing the accompanying files (XMP) —I just copy the photos I work with.

As for whether or not to keep the original RAW files, I personally make a backup copy of only very important images for me. Everything else is stored in DNG + separately processed JPG.

PS In no case do not call anyone to use DNG. Added your opinion, just as one of the many.