If you haven't heard of them, High Dynamic Range images are images that combine under and over exposed images to give a more natural look to photos.
The only way to apply an HDR effect to an image is to use a post processing tool such as Hydra. Hydra is a simple to use but powerful application that allows you to create HDR images from a series of regular photographs. According to the developers, Hydra uses a number of regular photographs (up to ten) with different exposures (darker and lighter) to create a superior one which is much closer to what the naked eye actually sees. This is apparently because a single photograph cannot represent the full gamut of light because of physical limitations in the sensor.
When you open Hydra, you're asked if you want to import photos on your hard drive, directly from iPhoto or just start using Hydra directly. If you just want to apply the HDR effect to just a few photos, then you might as well use Hydra directly as you merely have to drag and drop photos into the interface to get started. You can drag and drop up to a maximum of ten photos.
Once you've dragged and dropped the images you want to work with, you need to select the matching function from the toolbox on the right. Hydra requires you to select different reference points on the pictures and then try to align them as closely as possible isn't easy, although you don't have to be 100% spot on. Once you've matched your pictures, it's time to blend them.
Using the histogram view and sliders you can adjust your HDR image until it has all the shadows, light and detail that you're looking for. When that's done you then have to render the images which can take a while depending on how many images you've used, especially high resolution images. If you haven't matched up images very well, then you'll have trouble seeing any difference in your images at all. If you've done a good job, then you should notice some pretty impressive combination results. This unregistered version also leaves an "Unregistered" watermark across the final image along with the Hydra logo.
Hydra is a powerful tool and in the right hands, it can produce some impressive HDR images.
