Like most digital SLRs on the market, the Sony A-100 I bought last year gives you the option to save your images in “raw” format. That is, the raw exposure data off the camera’s array of light sensors with a bare minimum of processing. Simultaneously, it saves the same image ready-processed as a JPEG. The raw files are around 10Mb in size whereas the JPEGs are generally 2-3Mb.
Is there a point to raw format, though? It takes up a lot of space on my memory card so it is important to understand how to use it, and what it can do for you that JPEG can’t. I wondered if it might be aimed mainly at “advanced” users or professionals.
From the outset I set the camera to save both raw and JPEG versions of every shot. I had an instinctive fear of losing something I couldn’t get back if I only saved the JPEGs. The in-camera on-the-fly processing of the raw sensor data, to create the JPEG, is irreversible. You can recreate a JPEG from the raw data but not the other way around. And JPEGs are compressed. That must mean “lower quality” because JPEG compression is lossy.
I bought my Sony in Hong Kong while on an expensive holiday in the Far East, so I was blowed if I was going to throw away irreplaceable data underpinning my once in a lifetime shots of the great sights of China and Japan. My Compact Flash card had other ideas. I know I should have bought a more capacious one. I had my laptop on the holiday so I could keep transferring data to the hard disk each evening, but still found the card filling up far too fast in normal use. I switched to shooting JPEG only. I reasoned that I’d get better pictures by taking lots of JPEGs and picking the best, than by shooting fewer, in raw format, and hoping that the capabilities of raw format files might help me rescue some of the poorer shots.
All the same, I have now accumulated a lot of raw files in the 10 months I’ve had the camera. They account for a fair chunk of the 16 or so Gb of data I now have backed up on Amazon’s S3 data store in the cloud, which does cost me money. Not a lot I grant you, but over time it adds up. I’m really not sure whether those raw files are worth hanging on to. When, realistically, will I ever revisit any of them?
What might convince me about raw format is if I ever encountered a single shot where I was able to produce an image from a raw file that was visibly superior to the best I could have achieved working only with the JPEG saved by the camera. To date that has not happened, and it’s not that I have never dabbled with raw. I have used Sony’s own converter program, and also a free tool called Raw Therapee which is the personal project of one Gábor Horváth. To say that it is the work of a lone enthusiast, it has a stunningly professional interface and far more options and flexibility than Sony’s effort. But I am still unable to reap any real benefit from raw.
Maybe I just haven’t yet worked out how (or in which circumstances) to use it.
I don’t believe raw format gets you sharper pictures than JPEG, though some have claimed they can see a difference. Maybe at giant magnifications. Raw Therapee gives you a choice of three high powered demosaicing algorithms, but the results are awfully hard to tell apart – from the camera’s own JPEG and from each other.
If you’ve overexposed and blown the highlights you can, or so I understand, get back half a stop’s worth in raw. For the same space taken up on your memory card you can take four or five bracketed exposures, pick the best and save all that messing about on the computer.
I’m coming to the view that raw format is the sort of thing geeky enthusiastic amateurs get overexcited about. You know what I’m getting at. The obsession with technology and gadgetry at the expense of art. More time spent fiddling with settings in a raw converter program to no great benefit, as opposed to time spent in the field getting more and better pictures in the first place.
I really don’t think professionals make much use of raw. They really don’t have the time to piddle around trying to rescue imperfect shots with software. Their skill is what they do with camera in hand, not mouse and keyboard. Take lots of pictures, frame and expose them correctly. Pick the best and discard the rest mercilessly. Meet your client’s deadline and move on to the next assignment. Who the hell has time for raw?