Project 19: Focus Blur

I'm doing these projects a little out of order here, I hope that's not a problem.

For this project, I wanted a photograph that would be easy to experiment with. I chose three similar items so that I could directly compare the amounts of blur between them. I photographed three of my daughter's wooden trees against a black background (my halogen hob!). This gave me an image with bright colours, and bold, easy to select shapes.

Here is the initial image:

I use the smallest aperture on my camera, f/32, to retain as much depth-of-field as possible. I wouldn't normally use this for landscapes or stock photography, as it affects image sharpness a little. However, for this project I knew I wouldn't have to fight through the stock agencies' tough review process, so I didn't feel that it was too crucial.

I then created a duplicate layer, and blurred the background layer using a gaussian blur at a radius of 9 pixels. After selecting the front tree on the top layer, I inverted the selection and deleted the rest. This method would not work if the image had a detailed background, as it would blur everthing around the tree. However, for this image, it worked well:

Next, I created a further duplicate of the background layer. I blurred the background again, using the same settings. Then I isolated the middle tree on the duplicate layer and deleted the rest. Here is the final result:

Perhaps using a plain background was 'cheating', but it was useful in that it enabled me to practice the technique on the objects themselves. I have used a similar technique on portrait photos, and found that it minimised distractions in the background, thereby focusing attention on to the subject.

This is a useful technique, and I feel that it could be used to 'rescue' photos where depth-of-field is too deep - however, I would prefer to achieve the effect in-camera, if possible.


The photo below uses a combination of in-camera shallow depth-of-field and digital blur. It was taken for a competition entitled 'odd one out'. I used a very wide aperture and focused on the Buzz Lightyear figure - I then used digital blur to blur the aliens surrounding him so that Buzz was the only thing left sharp:

I came second in the competition, I think it made the judges smile! And yes, all of those individual aliens are actual models, not digitally duplicated. I confess to being a huge 'Toy story' fan! *blush*