Monday, June 22, 2009

An appreciation for RAW files

Up until now, I have not been able to truly appreciate what I can do with a RAW file. I mean, I know what a RAW file is (see explanation below)*. But does it really make much difference? I decided to learn more about it today. Am I glad I did!

Of course, you cannot do any adjustments on Exposure, ISO, Focus, Shutter Speed, and Aperture once that has been set in the camera. However, after an image is captured, a RAW conversion software allows you the flexibility to change the settings for white balance, tint, contrast, sharpness, saturation, and brightness at a later stage. While many of these adjustments can also be done on a JPEG file using a regular photo editing software, I have found that white balance is best fine-tuned in a RAW file. There is just no equivalent adjustment in a photo editing software (available adjustments are: Hue, Variations, Color Balance, Photo Filter).

The other adjustments (e.g. saturation, exposure, brightness), while available in a photo editing software, are much easier to make at RAW level. The RAW image file has a much richer range of colour information to play with. After all, RAW files are much bigger than JPEG files for a very good reason. RAW files are recorded in 12-bit or 14-bit, whle JPEGS have been compressed down to 8-bit, which gives you only 256 levels of tonal range. Guess what? I think I am going to start shooting serious pictures in RAW from now on. Photoshop is still useful, but I think I am missing half the picture (so to speak!) if I do not shoot in RAW. I am really excited about the prospects!

*RAW: this is the unprocessed data captured by a digital camera. Depending on the manufacturer, it could be named .NEF file, or .CRW, or .CR2 file, etc. For most consumer range cameras, the image captured is a JPEG file, which has been processed by the camera's CPU from raw data. Higher range cameras has the option to shoot in RAW format, which requires a RAW convertor for the picture to be viewed. Many RAW convertors also gives you the ability to make adjustments to the image, such as birghtness, contrast, white balance, etc.

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