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SHARPENING IMAGES IN ADOBE CAMERA RAW
This tutorial was prepared by Roy Killen and is copyright. It is part of the training materials provided for members of the Belmont 16 Ft Photographic Club and is not intended as a complete, stand-alone instruction package.
Comments and suggestions on this tutorial are welcome - they should be emailed to Roy Killen.
Before reading this tutorial you should read the tutorial on IMAGE SHARPENING - BASIC PRINCIPLES.
ADOBE CAMERA RAW SHARPENING DIALOGUE
When you open an image in Adobe Camera Raw and select the DETAIL adjustments tab (third tab from the left under the histogram) you are presented with the following options:
Before making any adjustments, you should set the image size to 100% using the pop-up menu at the bottom left of the screen - or just double-click on the "magnifying glass" icon at the top left of the screen.
There are four sliders associated with enhancing the sharpness of the image:
Amount - this simply varies the intensity of the sharpening by changing the amount of contrast that is added at edges (similar to the Amount slider in the Unsharp Mask dialogue).
Radius - this varies the width of the edge sharpening - much the same as it does in Unsharp Mask.
Detail - this determines what is considered to be an edge - much the same as the Threshold setting in Unsharp Mask.
Masking - this allows you to "cover" (mask) parts of the image so that they are not sharpened.
MAKING IT EASY TO SEE WHAT'S HAPPENING
If you have the image at 100% size AND you hold down the Alt key while moving the sliders you can see the sharpening effects much more easily.
Amount - the image changes to greyscale (monochrome) and the sharpening is easier to see than on a colour image.
Radius - the image is "greyed out" but the edges being sharpening are visible and the width of the sharpening halo can be seen to change as the slider is moved.
Detail - the image is "greyed out" but the edges being sharpening are visible.
Masking - with the setting on "0" the image is all white (indicating everything in the image is being sharpened). As the slider is moved to the right the parts of the image that are NOT being sharpened change to black.
FINDING THE OPTIMUM ADJUSTMENTS
As with any of the other approaches to sharpening you will find that the optimum settings for the sliders vary from image to image.
When you first open an image in Adobe Camera Raw, you should make all the necessary adjustments under the "Basics" tab (exposure, brightnessness, etc) before opening the "Details" tab to alter sharpness. When you do open the Details tab the sliders will be set at their default values (see the screenshot above).
The amount of sharpening you should apply depends a lot on how much further processing of the image you intend to do after you open it in Photoshop. If you intend to make all your adjustments in Camera Raw and simply transfer the image to Photoshop for printing then you will probably want to over-sharpen the image (as you would if you were preparing it for printing in Photoshop). However, if you plan to do a lot of work on the image in Photoshop it is best to limit the sharpening in Camera Raw to the point where the image looks sharp but is not over-sharpened. You can then process it in Photoshop and do further sharpening (perhaps with Unsharp Mask) immediately before printing.
If you want to compare your sharpened image with a non-sharpened image in Camera Raw just toggle on/off the Preview box that is located at the top right-hand corner of the image preview area.
When the Preview is OFF the image will be displayed with its default sharpening settings.
NOISE REDUCTION
Sometimes sharpening the image will add noise and this is most likely to be noticeable in "smooth" dark areas of the image. You can try reducing this noise with the Luminance and/or Colour sliders at the bottom of the Details (sharpening) dialogue.
WHY SHARPEN IN CAMERA RAW?
There are several reasons:
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You have more control over sharpening than you do with Unsharp Mask - because you can apply a "mask" directly in Camera Raw and see what effect it is having.
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It is a non-desructive process. You can re-open the Raw image and change the sharpening at any time.
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If you transfer the image from Adobe Camera Raw to Photoshop as a Smart Object then the sharpening process is completely reversible - you can swap backwards and forwards between ACR and Photoshop to fine-tune the sharpening even after making other adjustments in Photoshop.
ALTERNATIVE SHARPENING TECHNIQUES
All tutorials and images on this site are copyright.
This page last updated 26th August 2009 (RK)