I am in awe of J.K. Rowling.
The world she has created in her Harry Potter books has captivated my children, to the extent that it is hardly worth going to the library for our middle son, as I have huge difficulty getting him to read anything which doesn't have Harry Potter in the title!
I read all the books myself this January and February to better understand the attraction. The dark parts invaded my dreams, but the stories captivated me with their detail and character depth. Even the vehicles have stories behind them, my favourite of which is the Knight bus. In the film of Harry Potter and the Prisoner of Azkaban this triple decker bus speeds through the streets of London and squeezes itself between cars to avoid traffic. I really need a car that can do that!
The bus used in the film was created by combining three separate double decker buses and as a result wasn't able to go very fast. So the film makers faced a problem, how do you make it look like it is travelling at lightning speed? The answer is to slow down the reference time, that is, the speed of the other traffic. So by getting the cars in the surrounding traffic to go as slow as they could and the bus to go as fast as it could, the film makers captured a speed difference which they were then able to increase even further in post production.
Your DSLR also has the power to do this. You can slow down or speed up your reference time as you desire. Your shutter speed dictates how long your shutter stays open and therefore how long your camera has to see the motion in front of it. If you have a very fast shutter speed you will see a crystal clear image even if your subject is moving very fast. Conversely if you use a slow shutter speed you will see the motion in the image even if your subject is moving relatively slowly. This can magic images of your children like they have never seen before.
Keep in mind:
- finding the best shutter speed to capture the motion will require a bit of experimentation and will depend on the activity
- slowing down your shutter speed will let more light into your camera so make sure to take that into account when exposing your image
- if you shutter speed is too fast you won't be able to see the motion in the image, if it is too slow the blur will be so great that your subject will be unrecognisable
- you want the only blur in the photo to be motion blur so make sure you camera is held very steady ideally on a tripod.
For once it was me that managed the magic and I didn't even need a wand!