Adobe Photoshop CS5 for Photographers - Martin Evening [117]
Capture sharpening for scanned images
Scanned images may have already been pre-sharpened by the scanning software and some scanners do this automatically without you even realizing it. If you prefer to take control of the capture sharpening yourself you should be able to do so by disabling the scanner sharpening and using whatever other method you prefer. For example, you could use a third-party plug-in like PhotoKit Sharpener™, or follow the unsharp mask filter techniques I describe in the image sharpening PDF on the DVD. So long as you export your scanned images using the TIFF or JPEG format, you can open these images via Camera Raw, and use the same raw image sharpening methods as original raw files that I describe here.
So what about all those techniques that rely on Lab mode sharpening or luminosity fades? Well, if you analyze the way Camera Raw applies its sharpening, these controls have almost completely replaced the need for the Unsharp Mask filter. In fact, I would say that the Unsharp Mask filter, has for some time now been a fairly blunt instrument for sharpening images, plus I don't think it is advisable to convert from RGB to Lab mode and back again if its unnecessary to do so. Compare the old ways of sharpening (including the techniques I described in my previous books) with the Camera Raw method and I think you'll find that this is now the most effective, if not the only way to capture sharpen your photos.
How to use the Unsharp mask filter
The main book no longer covers the manual pre-sharpening techniques that use the Unsharp Mask filter. However, you will find a 20 page PDF document on the DVD that fully describes how to work with the Unsharp Mask filter sliders and outlines some of the advanced ways you can use the Unsharp Mask filter to achieve better capture sharpening results.
Process Versions
As I mentioned in Chapter 3, in order to distinguish between Camera Raw 6.0 and pre-Camera Raw 6.0 sharpening and noise reduction, Camera Raw has seen the introduction of Process Versions. As a result of this, legacy photos that have been edited via Camera Raw or Lightroom are classified as using Process Version 2003 and all photos edited subsequently in Camera Raw 6.0 can be edited using the new Process Version 2010 rendering.
Improvements to Camera Raw sharpening
Camera Raw 6.0 now offers better demosaic processing, sharpening and noise reduction. The combination of these three factors has led to better image processing from this latest version of Camera Raw. Having said that, it should be noted that only those cameras that use the three-color Bayer demosaic method are affected by this change. The demosaic processing for other types of sensor patterns, such as the four-color shot cameras and the Fuji Super CCD, have not been modified. However, improvements have been made in the demosaic processing for specific camera models. For example, an improved green balance algorithm addresses the problem of maze pattern artifacts which were seen with the Panasonic G1 and this may also improve the image resolution for some other camera models too.
Let me try and explain what exactly has changed and how Camera Raw is now different. We can start by looking at the two image examples shown in Figure 4.1, where the top image shows a photograph processed via Camera Raw 5.0 and the bottom one shows the same image processed via Camera Raw 6.0 in Photoshop CS5 using Process Version 2010. These examples include a section that's been enlarged to 400% so that you can see the difference more clearly. The first thing to point out is that the new demosaic process is now more ‘noise resistant’, which means it does a better job of removing the types of noise that we find unpleasant, such as color artifacts and structured (or pattern) noise. At the same time, the aim has been to preserve some of the residual, non-pattern noise which we do find appealing. The underlying principle at work here is that colored blotches