Adobe Photoshop CS4 review

Adobe Photoshop has had a fim grip on the world of professional photo editing because of its unmatched pixel-processing power.

Speed is of the essence, and this latest version feels more responsive, offering smooth and instant zooming, panning and onscreen rotation with an OpenGL-compatible graphics card. New CS4 interface features such as the workspace switcher and the window arranger add to working efficiency. Adobe has made a host of smaller tweaks, such as interactive onscreen brush resizing and keyboard short cuts for temporarily switching between tools.

Photoshop's tools have developed over many years. With Photoshop CS4, however, Adobe has gone back to the drawing board and reworked its entire approach. It introduces a new Adjustments panel, which allows you to apply core colour corrections quickly as non-destructive layers. This means that any changes made to pixel values are not permanent, so you can fine-tune them as desired to get the best possible results.

Photoshop has offered adjustment layers since version 6, but they were hidden away and awkward to use. Now, rather than having to call up dialog boxes to make changes, you can simply select an adjustment layer, and its parameters appear in the Adjustments panel ready for live onscreen control. For the core Curves and Hue/Saturation adjustments, Photoshop CS4 goes even further: simply click on the image and drag up to brighten those tones or down to darken them; click on a colour and drag right or left to change its saturation. This isn't just powerful and intuitive, it's actually enjoyable.

The main disadvantage of adjustment layers is that their corrections automatically apply to the image as a whole. The solution is to add a mask so that you can control precisely where the layer is applied. With Photoshop CS4 this option is made more accessible and more powerful thanks to a dedicated Masks panel. It brings together important commands for controlling the density and edges of your mask and offers quick access to the Select Colour command, which has been revamped to let you select multiple masking colours live on your image.

Other major enhancements in Photoshop CS4 focus primarily on bringing the best out of your images. Its layer-blending capabilities have been improved, so you can create panoramas with almost seamless blends and bring out extraordinary dynamic range effects from multiple shots with different exposures. The core retouching tools are now more intelligent and preserve an image's underlying tonal quality. The Camera Raw utility - for colour-correcting RAW files as you import them - has also been upgraded, and now allows you to make localised, mask-based, non-destructive adjustments.

With each new release of Photoshop, Adobe also likes to add something a little special. Using the new Content-Aware Scaling command you can simply drag on the edge of an image to make it wider or narrower, and Photoshop automatically keeps areas of interest unchanged. The first time you see it in action it's hard to believe your eyes: people in the image remain properly proportioned, but slide neatly together as Photoshop smoothly removes the spaces between them.

Photoshop CS4 isn't simple to use, and if all you need is a program that lets you quickly enhance and organise your digital photos, you're better off with Photoshop Elements or even the free Google Picasa. However, if you want the best pixel-editing and compositional power available for in-depth work on a single image, nothing comes close to this.