3 Cool Tricks You Can Only Do In Photoshop CS4

To use the tool, you simply apply a curves adjustment layer and click the small hand button, top left of the Curves palette. As you hover over your image you'll see the eyedropper cursor, which shows you where that part of the image falls on the curve line.

Big deal, right? It's always done that. But try clicking on a specific part of the image you would like to brighten (in the example, the walls) and drag upwards. You'll see those tones immediately lighten and your curve line will reflect that adjustment in real time.

In our example, due to the previous action, the candles have lost some of their brightness. To bring those highlights back, we can target them by simply clicking directly on them and dragging down. Again, the curve reflects your adjustment.

Now, if you're already a whiz with curves, you might not see great appeal in this tool. After all, there are other ways to achieve the same result—as long as you know what you're doing. However, if you're a visual thinker who has perhaps found it difficult to equate what's happening in the graph to what's happening in your image, this is a great connector. Working directly on the image certainly feels more natural to me.

3D Painting

Okay, yes there was 3D in CS3 but let's be honest: it wasn't hugely useful, was it? You jumped out into a separate applet to use a limited set of tools. It was a passable imitation of 3D at best. The new 3D implementation definitely raises the bar significantly.

Firstly, there is no jumping out of the application—all 3D manipulations are performed in the main workspace, side-by-side with the 2D tools. You can open a 3D file directly in Photoshop (U3D, 3DS, OBJ, DAE, and KMZ) or add a 3D layer to an existing project.

Secondly, the new model controls are a big improvement. While the toolbar now contains 3D Rotate, 3D Move and 3D Scale Tools, Adobe have also added a nice 3D Axis tool that overlays your model, allowing you to orientate it without leaving the workspace.

But perhaps most impressive of all is the way Adobe have been able to make their 2D tools operate on 3D surfaces. Grab your Brush Tool, set a color, and start painting. Paint diffusion rates and angles are all controllable.

It doesn't end with flat color either. Switch the Paint Mode and you can paint with Bumps, Glossiness, Opacity, Shininess, Self-illumination, and Reflectivity.

You can even use the Merge Down option in the Layers palette to apply a 2D image (say, a logo) to your 3D object. That's pretty nifty in my book.

In reality, the new 3D tools in Photoshop probably deserve a dedicated article; however, I think it suffices to say that as of CS4, 3D is a fully-fledged Photoshop citizen, rather than a tacked-on afterthought.

Summary

It's always difficult making the call as to when to upgrade an expensive application like Photoshop—especially if you're shelling it out of your own pocket, rather than your boss's. No doubt your current version worked yesterday and will continue to do so tomorrow.

However, if the question of upgrading is on your mind, with the addition of features like CAIR, there are probably more compelling reasons to take the plunge this time than there's been for a any of the past two or three versions.