Adobe Photoshop CS5 for Photographers - Martin Evening [115]
DNG Converter
Adobe have made the DNG converter program ( Figure 3.80 ) available as a free download from their website: www.adobe.co.uk/products/dng/main.html . The DNG converter is able to convert raw files from any camera that is currently supported by Camera Raw. The advantage of doing this is that you can make backups of your raw files in a file format that allows you to preserve all the data in your raw captures and archive them now in a format that has a greater likelihood of support in the future. I personally feel quite comfortable converting my raw files to DNG and then deleting the original camera raw files. I don't see the need to embed the original raw file data in the DNG file, since this unnecessarily increases the file size. However, if you do feel it is essential to preserve complete compatibility, then embedding the original raw file data does allow you to extract the original native raw file from the DNG at some later date. The advantage of this is it provides complete compatibility with the camera manufacturer's software. The downside is that you will more than double the size of your DNG files.
Figure 3.80 The DNG Converter program
Maintaining ACR compatibility
If you refer back to page 136, you can read how it is possible to use the DNG Converter program to convert new camera files to DNG and thereby maintain Camera Raw support with older versions of Photoshop and Camera Raw.
Chapter 4. Sharpening and Noise Reduction
This chapter is all about how to pre-sharpen your photographs in Photoshop and reduce image noise. Here, I will be discussing which types of images need pre-sharpening, which don't, and what are the best methods to use for camera captured or scanned image files.
In previous editions of this book I found it necessary to go into a lot of detail about how to use the Unsharp Mask filter and the Photoshop refinement techniques that could be used to improve the effectiveness of this filter. Now that the sharpening and noise reduction controls in Camera Raw have been much improved, I strongly believe that it is best to carry out the capture sharpening and noise reduction for both raw and scanned TIFF images in Camera Raw, before you take them into Photoshop. The first part of this chapter is therefore devoted entirely to Camera Raw sharpening and noise reduction.
When to sharpen
All digital images will require sharpening at one or more stages in the digital capture and image editing process. Even if you use the finest resolution camera and lens, it is inevitable that some image sharpness gets lost along the way from capture through to print. At the capture end, image sharpness can be lost due to the quality of the optics and the image resolving ability of the camera sensor, which in turn can also be affected by the anti-aliasing filter that covers the sensor (and blurs the camera-focused image very slightly). With scanned images you have a similar problem: the resolving power of the scanner sensor and the scanner lens optics can lead to scans that are slightly lacking in sharpness. These main factors can all lead to capture images that are less sharp than they should be.
Real World Image sharpening
If you want to learn more about image sharpening in Camera Raw, Lightroom and Photoshop then I can recommend: Real World Image Sharpening with Adobe Photoshop, Camera Raw, and Lightroom (2nd Edition) which is available from Peachpit Press, ISBN: 0321637550. The first edition was authored by Bruce Fraser. This new version is an update of Bruce's original book, and now coauthored by Jeff Schewe.
When we come to make a print, all print processes cause some sharpness to be lost, so it is always necessary to add some extra sharpening at the end, just before sending the photograph to the printer. Also, between the capture and print