Recently Adobe PhotoShop (PS) improved its interface for dealing with Camera Raw Files with the release of CS2. As this is the first and most important step in dealing with raw files I thought it would be helpful to provide some infomation for those dealing with them and hopefully provide a bit more to aid in your understanding.
RAW files
We can consider raw files as undeveloped images, as if they were film from your camera (film negs/trannies), the conversion process is the developingof these images (colour prints).
Raw files contain both image data and information about how the image was originally shot, e.g. camera model, shutter speed and aperture, within a high compression format.
Transformation in photoshop
The conversion from Raw to colour image within the Camera Raw Window (CRW) follows several steps prior to any operator adjustments, including White Balance, Gamma correction and Noise reduction.
The Raw file allows a huge amount of control over the image before its converted, however the auto settings, in my experience, are rarely accurate. Raw files contain far more information than PS can handle due to their bit depth (12, 16, 24 bit) therefore global colour retouching within the CRW is very important prior to converting to a photoshop file (8 bit). Information that PS cannot handle is thrown away! Raw files tend to be very dark due to this overload of information but properly compensated raw files will result in a even distribution of colour when converted.
Converting the raw file creates an edited copy of the file for use in PS (tif/psd/eps/jpg etc) and an xmp file which reports the changes made to the raw file. Its sensible to keep all 3 files together for future use.
Settings in the Camera Raw Window
Most options within the CRW are obvious, but as a guide:- Temperature and Tint are similar to Variations in PS. Exposure, Shadows and Brightness are similar to using Levels. Detail Sharpness helps with improving how sharp the image is and lowering noise. Lens reduces fringing and vignetting. Curve provides adjustments over all plates.
Calibrate provides fine tuning of the seperate plates plus the ability to save settings for particular cameras accounting for errors eg colour hues. Crop Size and Resolution allow us to upsize our image taking advantage of the larger bit depth of the raw file when converting to PS.
All these settings can be saved for comparison or for subsequent images.
Final notes
There’s far more information available online concerning Camera Raw Files and I thoroughly recommend exploring the CRW as this is an area that promises further development from Adobe.
