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Tuesday, December 11, 2007

Fixing Vignetting in Adobe Camera Raw

Artists and photographers purposefully use vignetting for various reasons related to their final composition. Vignetting is a reduction of brightness or saturation at the periphery of the image (especially the corners) as compared to the center. When artists and photographers do it, it's a purposeful choice used to further their vision. When a CCTV camera does it, it's a defect.

Until recently, the fix for this involved masking and a lot of time and effort. Now, we have the ability to work on a majority of our images in Adobe Camera Raw. Built in to ACR is a feature to compensate for this defect.

Back to our noisy night picture. Notice the darkening around the edges and corners. This is classic vignetting and it can be compensated for in Adobe Camera Raw. Found in the Lens Correction tab (6th from the left), the Lens Vignetting sliders are soon to be your good friends. They work quite simply:
  • Increase the Amount slider to lighten the corners, or decrease the Amount slider to darken them. 
  • Decrease the Midpoint slider to apply the adjustment to a larger area away from the corners, or increase the Midpoint slider to restrict the adjustment to an area closer to the corners. 
It's really that simple. The preview pane let's you see the results before you take the image into Photoshop for further correction. Because you are working in ACR, the effect is applied non-destructively. You can always clear the settings in Bridge (unless you've saved the image) by right-clicking on the image and choosing Develop Settings>Clear Settings.

I am sure that this little time-saver will become a welcome addition to your Forensic Photoshop work flow. You won't need it every time, but it will definitely save you time and effort when you do.


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