Adobe Photoshop CS Review
By Vincent Bockaert, September
The new Version 8 of Adobe Photoshop is now called "Adobe Photoshop CS" and is part of the newly announced Adobe Creative Suite which combines full, new versions of Adobe Photoshop CS with ImageReady CS, Adobe Illustrator CS, Adobe InDesign CS, Adobe GoLive CS, Adobe Acrobat 6.0 Professional, and the new "Version Cue" file version manager, which lets you easily track interations and quickly locate files. Note that this review of Photoshop CS is based on a (very recent) beta version, so screen captures and functionality may not be representative of the full and final product.
Photoshop CS is no doubt the most significant Photoshop move towards digital photographers. Although this upgrade also provides exciting new features for general users, web designers, and even video editors, this article will focus on some of the exciting new features most useful to digital photographers.
The simplicity of the Photoshop CS interface is as deceiving as its
predecessors and at first it appears as if little has changed, making
from Photoshop 7 to Photoshop CS very natural, preserving most of your
Photoshop learning curve. However, a closer look reveals a large number
of exciting new features ranging from major things such as RAW support,
and the Histogram Palette to minor things such as Crop and Straighten
and the Bicubic Smoother and Bicubic Sharper interpolation options.
The RAW part of the separate Photoshop 7 Adobe Photoshop Camera RAW &
JPEG 2000 Plug-in Bundle which was sold separately is now an integrated
part of Photoshop CS and has become substantially more powerful. JPEG 2000
delivers superior quality for the same compression ratio (or superior
compression ratios for the same quality). However, since no cameras currently
support JPEG 2000, support for this format is available through a separate
plug-in that ships with the software.
Unlike the more universal JPEG format, RAW comes in many flavors, depending
on the camera brand. It is usually processed by software provided by
manufacturer or specialized third party software. Adobe Photoshop CS
covers most RAW formats available today. However, given the proprietary
of the various RAW formats, the RAW data may not always be read 100%
correctly. For instance, the white balance of Nikon Coolpix 5000 images
unnatural, which was not the case using Nikon's own Nikon Capture 3.5.
That being said, it was relatively easy to fix the white balance by clicking
in a non-specular white area, followed by a minor tint adjustment. Further
adjustments can be made via the advanced "Calibration" tab.
Moreover, you can save your settings and use these as a start for subsequent
images from the same camera so you will not have
to make these adjustments every time.
Before white balance and exposure adjustments
After white balance and exposure adjustments
The "Adjust" tab of the RAW dialog box has also exposure, shadow, brightness, and contrast sliders. Although these have of course a similar effect as Levels, a per channel Levels adjustment feature would be desirable. Also missing is a (per channel) Curves adjustment, present in higher end RAW software. The "Adjust" tab has also a main saturation slider, while the advanced "Calibration" tab allows you to fine tune the hue and saturation of the individual color channels, as well as the shadow tint. Even though Photoshop CS features now a new Histogram Palette, the RAW dialog box also features live histograms.
Analyzing and developing noise reduction methods is one of my favorite digital imaging activities. With Photoshop CS, Adobe has created an excellent noise reduction method for RAW files via the "Detail" tab. It would be great to have this feature implemented for JPEGs as well.
Before noise reduction
After noise reduction
The color noise reduction and luminance smoothing sliders allow you to reduce color and luminance noise independently. The latter should be used with caution because it can quickly lead to an artificial "water paint" effect with too uniform surfaces. Overall, the noise reduction performs very well and preserves image detail and edge sharpness. However, there is still room for improvement on large uniform areas as shown in this example which just focuses on the red channel where the noise is most visible. The wavy pattern in the sky is typical for automated noise removal methods, and is the result of blurring the LAB color channels, thereby smoothening color noise while leaving the lightness/luminance channel (and hence sharpness) intact. Manual noise removal can lead to much more uniform skies but requires more time, the typical digital imaging trade-off.
RGB composite image after noise reduction
Red channel before
Red channel after Photoshop CS RAW
Red channel after
I also noticed that when this particular Nikon *.NEF image was opened in Photoshop CS without noise reduction, the noise was stronger (albeit more looking like real film grain) than the typical noise present when opening the same file with Nikon Capture 3.5, indicating the RAW data are processed differently in both programs. A more detailed noise analysis can be found on my website http://www.VincentBockaert.com.
Chromatic aberrations are typically removed by applying a local desaturation in the corresponding color channels. The "Lens" tab of the RAW dialog box provides a very easy to use and effective way of reducing certain types of chromatic aberration as shown in this example. I look forward to having this feature implemented for JPEGs as well.
Before chromatic aberration removal
After chromatic aberration removal
There are also two sliders to reduce (symmetrical) vignetting.