By way of an update...

If you're shooting for a picture library, this is great. If you don't have a long enough lens and you need to crop, this is great. If you have good lenses and don't go over A3 with a decent DSlr, you may not really need this...

What's this about? GF is an up-sampler, that is it makes a large file size from a small one. It does this by looking at 'Fractals' whereas Photoshop looks at the surrounding pixels and adds more similar ones in.

GF "starts by analyzing ever-decreasing sizes of pixel blocks in your image looking for repeating natural patterns at different sizes. These are known as fractals. Fractals are common, naturally repeating patterns found everywhere. For example, a river system viewed from space has the same shape as the veins in a leaf. These are both fractal patterns at very different scales. The great thing about fractal patterns is once you find them they can be scaled to any size without loss in detail. This allows Genuine Fractals 5 to resize your image over 1000% without losing sharpness and edge detail." - quoted from the OnOne website.

So why would you want this to happen? Put simply, this process enables one to produce poster size images from files that would lend themselves to somewhat smaller print sizes.

The top picture, taken at the Pytchley Point-to-Point recently, has been cropped in GF to leave just the female rider... you see no discernable drop in quality!

This example did not stretch the software i.e. I could have gone further...

OK so I had to... the final picture does show some loss but it would be massive if printed!

Sorry for the file sizes - it's worth noting that the 'real' files are 8 times larger than this!