Yesterday we had a few other photographers stop by the studio for a discussion on lighting equipment and techniques. Lurking in the background was a related topic – deciding what file format to record in. Choosing a file format means you are choosing how much information you are recording while shooting. In this case, we were talking about shooting in JPEG vs. RAW, although the discussion could be extrapolated to any compressed vs. uncompressed comparison.
I have never intentionally shot in JPEG for photography – I’ve always been a die-hard RAW shooter. That said, I’ve never actually sat down and done any kind of testing to see just how different the two formats are. So I thought it appropriate to give it a shot (pun intended).
One of the major advantages of shooting in RAW is the ability to manipulate exposure in post-production. And I do mean “manipulate” and not “correct” – as Matt was quick to point out that people might think “Well, why wouldn’t you just shoot it correctly in the first place?” I’ll get to that in a later post.
This test was fairly simple – I set up a bottle of rum on a stool in our studio, and I took a two photos of it that were both equally (and dramatically) underexposed. Both photos looked basically black out of the camera, but one was recorded in JPEG and the other in RAW. I wanted to see just how much information was actually there.
After pulling up the exposure on the two images, the difference was immediately clear, although not without a surprise: the JPEG file actually contained far more information than I was expecting. Of course, it paled in comparison to the RAW file. Color, detail, and contrast in the JPEG file were all woefully deficient when compared to the raw file after a similar exposure adjustment. Now, neither is pretty, but that’s not the point. At this level any qualitative judgment has to be made in a well-defined context.
The detail shot makes the difference abundantly clear. The JPEG image is peppered with blocky noise artifacts and seriously lacks both color information and detail. The rum looks black, because there is just no information there to show otherwise. Applying a few simple warm color adjustments only exacerbates the problems. This is what colorists generally mean when they say that applying color adjustments to a compressed image causes the image to “fall apart.” And although the RAW file is surely not something I would submit to a magazine, it holds up very well.
Be sure to check out the other blog posts in our RAW vs. JPEG series: