Here's the tree photographed without any extra zoom effect:
At this point I've used manual focus to ensure that the tree is in focus with the zoom at its maximum width.
The zoom burst picture is created by slowing the shutter and zooming steadily in on the subject. I slowed the shutter to 1/4 second which of course allows more light into the picture, so I used the exposure compensation option to reduce the exposure by five stops. Keeping the camera as steady as possible, I zoomed in on the tree which resulted in the following picture:
I like the technique and it's something I will continue to experiment with. There are numerous good examples of similar photographs on-line and I'd particularly like to try some night-time work and crowd photography.
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