Though modern day photography allows you to go a long way, adding computerized post processing has opened up avenues that were thought impossible once upon a time. HDR is one of those innovations.
HDR or High Dynamic Range imaging is a technique used to create a balanced exposure throughout the image. So in tricky shots like landscape, where the lighting often makes it impossible to illuminate the complete scene without over or underexposing the picture, HDR allows you to combine a series of variably exposed pictures to illuminate the entire picture evenly, making every shadowy nook and cranny as visible as the brightly lit areas.
A great example of the work done using this technique is the image below showing the New York skyline at night.
Notice how the brightly lit areas don't appear overexposed, while the shadowy areas too are quite well illuminated. A picture like this would be impossible to take without the help of HDR.
HDR imaging is fast gaining popularity among professional as well as amateur photographers, to the extent that you can find a tremendous community support for it all over the internet. So with this feature, we'll show you how you can achieve this effect yourself.
Since it's an advanced technique, slight prior knowledge of Photoshop is required.
What you need
The biggest problem you may face with HDR is that because the whole concept is based primarily on image exposure, a normal digicam will not be good enough for this, as the noise levels in consumer digital cameras tend to appear more on higher exposure settings. Still if you think your camera can pull it off go for it. What I would recommend is a D-SLR.
Practically any D-SLR should do the trick here. I have personally used Nikon D-40X in my example here, and the results were pretty good. So I can safely assume that you don't necessarily need to go in for a higher-end D-SLR to try out HDR.
The second most important thing for the process is a tripod. Flat surfaces are a good replacement for everyday shots, but when you need to take multiple shots of the exact same scene, you need something a little more reliable. That's why the tripod is a must for HDR.
Photoshop CS3 is what I have used for this example, as personally I find it easiest to use among the applications I have tried. In case you're looking for a free application for HDR you can try using Qtpfsgui.
Answer to your question about the D40...
