Yesterday, we covered photo and folder naming. It seemed to me that it was worth covering an important topic about the photos themselves - the format I choose to use. I won’t make you read to the end - I prefer DNG. I shoot in RAW and convert all of my RAW files to DNG right upon import to Lightroom (yip, I don’t have any RAW files on my computer, just DNGs). Read on for more information.

Digital SLR cameras can shoot JPEGs. The downside is that they don’t carry all the original information - they become slightly compressed and are only 8 bit. Luckily, digital SLR cameras can also shoot in RAW, a format that stores the photo uncompressed and in 16 bit. While the photos aren’t necessarily twice as good as JPEGs, they do carry important details in highlights, shadows and other areas. That allows potential recovery of all white or ‘blown out’ areas and generally more flexibility in post-processing. (For a more extensive look at JPEG vs RAW, you can go to http://digital-photography-school.com/blog/raw-vs-jpeg/).

RAW Drawbacks

Shooting RAW does come with a few drawbacks, though. One is that each camera has its own RAW format. Personally, that frightens me a little bit. I don’t like thinking that all the pictures I took are stored in a format that only the particular manufacturer (Canon in my case) is privy to.

Second, the files can end up quite a bit larger than a RAW counterpart. When taken with a 10MP camera, a typical JPEG is 3-4 MB and a RAW file is 10MB.

Lastly, non-destructive editing and other metadata can’t be stored directly in a RAW file - they require something called a sidecar file. So, for every RAW file processed with a program like Lightroom or Camera RAW, a second file is created that contains nothing but information about the changes made. If those changes need to be saved, that file always has to be toted around with the RAW file. It can get quite annoying.

Why DNG Rocks

Enter DNG. DNG is a RAW archival format created by Adobe. Adobe created it to address the outbreak of RAW formats, allowing a common, documented format that has a higher chance of being documented for years to come. Don’t forget that Adobe also created PDF and a few other long-lasting file formats. They have a history of getting this sort of thing right more often than most others. For me, benefits of equal size include:

• Smaller File Size: They use a compression that doesn’t sacrifice quality, allowing 50% decrease in file size in some cases.
• Data Stored in the File: Non destructive editing and metadata are stored in the file itself, eliminating the need for sidecar files.

Image Format Comparison

See the following for a summarized comparison of JPEGs, RAW and DNG. Overall, I prefer DNG. It keeps file sizes down, is open format, doesn’t need a sidecar and maintains all the original data. In certain circumstances, JPEG can come in handy. Having sharpening and other settings automatic can reduce processing time.

For complete information on DNG, straight from the source, check out the Adobe page on it here.