I'm learning manual settings for high shutter speeds at the moment, trying to capture birds in action. However, the weather hasn't been very good. The faster the shutter, the darker the image, so I had to compensate by increasing the ISO - which makes the photos dottier / noisier / smudgier, just so that the photo would be bright enough to be visible. What I really need is a 'bright' 'fast' lens, with telephoto zoom. These photos were just a small bit of a bigger photo, and I cropped around the bird. So, detail isn't great, and it's dotty / noisy, but I did manage to capture and freeze-frame the birds in flight!
Luckily, the graininess of the image isn't visible when small, so printed at a normal 3 x 5 photo size, it would still look really great. The image quality loss is only noticeable as the image gets bigger (such as on a large monitor or a poster)