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Down with JPEG, up with raw!

A little digital rant

Plain consumer digicams all save their images directly to JPEG files. This is a Very Bad Idea, quality-wise. The most obvious one is that JPEG is a highly compressed and very "lossy" file format, so much subtle information, originally captured by your camera's sensors, is therefore thrown out. And if you open up any JPEG file in Photoshop or other editing programs, make some tiny changes, like cropping, and save it as JPEG — more damage is again done to your image. Do this four-five times and your formerly so great photo will turn into visual manure. JPEG is a quality killer, and should only be used as a final viewing format, like on web pages, and never as an intermediate storage and editing format. Never.

Down with proprietary raw, up with public DNG!

A raw workflow has an optional step, which is still very important: to convert your vendor-specific, proprietary and unpublished raw files into the open-standard DNG (Digital Negative) format, created by Adobe. I use the free DNG Converter from Adobe for this, it creates around 20-25% smaller raw files than the MRW files from my great Konica Minolta DiMage A2 camera, losslessy compressed, and it's a batch program which takes no brains or time to run — especially if run from inside Adobe Bridge, the image browser in Adobe's CS2 suite. I perform that DNG conversion on all my MRW raw files and then delete the MRW files.

The professional photo community is now lobbying camera vendors like Nikon, Canon, Minolta and Sony, to either open up their proprietar raw formats or, preferably, to drop their old, closed formats and adopt the DNG format — so instead of there being 2,323 different raw formats, most bound for extinction, there will be one raw format, which is published and open, thus avoiding long-term problems with accessing our precious "digital negatives".

But the raw formats available in the better digicams and dSLRs is are quite different animals. They are direct captures of the camera's RGB sensor, with no intermediary conversion algorithms, except for an analog-to-digital conversion and, ordinarily, no lossy compression. Also, raw formats usually have many more bits of information for each of the RGB color channel, usually 12 bits vs. 8 bits in JPEG, which results in smoother gradations and much more "leg-room" — 4096 levels vs. 256 — for heavy tweaks and edits both in the raw converter and in Photoshop.

However, raw files are useless before they are converted into another file format, so they can be edited, exported and printed — that's their downside. Also, they take up much more space on our memory cards and hard drives than does JPEG files — typically 3-5 times as much. And if you work with them in Photoshop as 48-bit images, they consume twice the working RAM as 24-bit images. But all of these downsides are worth it — if you are seriously concerned about image quality.