Monday, June 7, 2010
Creating motion in a still photograph
A method that I've been using a bit lately with my young son is using fast shutter speeds to create a series of pictures, and then blending them in post-production to create a still 'video' of his crazy antics.
Now bear in mind that he's just turned 7 and that wall is about 30 feet off the ground and you'll understand why we don't invite his mother down for a look! It was taken yesterday at the Esplanade skateboard park down on the foreshore here in Cairns.
Being a morning shot the bowl is certainly a bit darker than I would like - so I'm planning on coming here in the afternoon one day. Anyway how I do this one.
The first thing is to shoot the entire sequence from drop-in to finish with a really fast shutter speed and a high frame rate - in my case about 7 photos per second. Then you end up with 20 to 30 pictures. You need to have the camera either on a tripod, or held very steady, because everything else in the picture apart from the moving subject has to remain the same in each picture. So no moving! Also it's best to have your camera on Manual exposure so that your exposure will be the same for each image in the sequence. And if you're shooting Jpeg make sure you put it on a preset white balance (not automatic) so the White Balances are the same across all the pictures.
I bring the photos into Bridge and, after re-naming and adding Copyright metadata I open up the images one at a time in Photoshop to start the blending process.
I start with my bottom image - which for convenience sake I always make the last image in the frame. Then I gradually add more images on top of this base to create a multi-layered PSD file. Now you have lots of pictures on top of one another, with only the top one visible.
So to get the multi-sons to all appear in the bottom layer I just have to rub out certain parts of the top layers. And because I've got the camera rock steady the only parts I need to rub through are the bits where my son is. You could use the eraser tool I guess but I tend to use a Layers Mask and paint it black. That way if I mess up I can change my brush colour to white and then paint back the mistake.
Because the background of the picture is exactly the same in each shot you only have to erase the bits where my son is. So that's a tiny little bit of painting each time and you don't have to be too exact because everything around him is exactly the same. Even if you erase an area of the background, because it doesn't change from one layer to the next you'll never notice. Give it a go - it's great fun. You can also use this technique to create a picture with multiple versions of yourself doing funny things all in the one frame. Just put the camera on a tripod and use the self-timer. The only limit is your imagination.